Just Accepted
Display Method:
Published:
, doi:10.1088/1674-1137/ade95f
Abstract:
By analyzing a
\begin{document}$\psi(3686)$\end{document}
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data sample containing
\begin{document}$(107.7\pm0.6)\times10^{6}$\end{document}
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events taken with the BESIII detector at the BEPCII storage ring in 2009, the
\begin{document}$\chi_{c0}$\end{document}
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resonance parameters are precisely measured using
\begin{document}$\chi_{c0,c2} \to \pi^+\pi^-/K^+K^-$\end{document}
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events. The mass of
\begin{document}$\chi_{c0}$\end{document}
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is determined to be
\begin{document}$M(\chi_{c0})=(3415.63\pm0.07\pm0.07\pm0.07$\end{document}
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) MeV/
\begin{document}$c^2$\end{document}
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, and its full width is
\begin{document}$\Gamma(\chi_{c0})=(12.52\pm0.12\pm0.13)~{\rm{MeV}}$\end{document}
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, where the first uncertainty is statistical, the second systematic, and the third for mass comes from
\begin{document}$\chi_{c2}$\end{document}
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mass uncertainty. These measurements improve the precision of
\begin{document}$\chi_{c0}$\end{document}
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mass by a factor of four and width by one order of magnitude over the previous individual measurements, and significantly boost our knowledge about the charmonium spectrum. Together with additional
\begin{document}$(345.4\pm2.6)\times10^{6}$\end{document}
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\begin{document}$\psi(3686)$\end{document}
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data events taken in 2012, the decay branching fractions of
\begin{document}$\chi_{c0,c2}\to\pi^+\pi^-/K^+K^-$\end{document}
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are measured as well, with precision improved by a factor of three compared to previous measurements. These
\begin{document}$\chi_{c0}$\end{document}
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decay branching fractions provide important inputs for the study of glueballs.
By analyzing a
Published:
Abstract:
Vector-like quarks (VLQs) are introduced in many new physics senarios beyond the Standard Model (SM) to address some problems faced by SM. In this paper, we explore the pair production of TeV-scale vector-like B quark (VLQ-B) at the future 3 TeV Compact Linear Collider (CLIC) in simplified effective lagrangian framework. We consider the decay modes of
\begin{document}$ B\rightarrow bZ $\end{document}
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and
\begin{document}$ B\rightarrow bh $\end{document}
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followed by hadronic decay ofZandhbosons. The large mass of VLQ-Bwill induce highly boosted bosonsZorhwhich are more likely to form as fat-jets. By performing a rapid detector simulation of the signal and background events and clustering the jets with a large radius R, signal-background analyses are carried out. And the exclusion limits at the 95% confidence level and the 5
\begin{document}$ \sigma $\end{document}
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discovery prospects are obtained with an integrated luminosity of 5ab−1.
Vector-like quarks (VLQs) are introduced in many new physics senarios beyond the Standard Model (SM) to address some problems faced by SM. In this paper, we explore the pair production of TeV-scale vector-like B quark (VLQ-B) at the future 3 TeV Compact Linear Collider (CLIC) in simplified effective lagrangian framework. We consider the decay modes of
Published:
Abstract:
The rigorous calculation of the spin-orbit terms in the three-quark system is realized based on the Gaussian expansion method and the infinitesimally-shifted Gaussian basis functions in the framework of the relativized quark model, by ignoring the mixing between different excited states. Then, the complete mass spectra of the singly heavy baryons are obtained rigorously, under the mechanism of the heavy-quark dominance. On these bases, the systematical analyses are carried out for the reliability and predictive power of the model, the fine structure of the singly heavy baryon spectra, the assignments of the excited baryons, and some important topics about the heavy baryon spectroscopy such as the missing states, the 'spin-orbit puzzle', the clustering effect, etc. The result confirms that under the heavy-quark dominance mechanism, the relativized quark model can describe the excitation spectra and the fine structures of the singly heavy baryons correctly and precisely.
The rigorous calculation of the spin-orbit terms in the three-quark system is realized based on the Gaussian expansion method and the infinitesimally-shifted Gaussian basis functions in the framework of the relativized quark model, by ignoring the mixing between different excited states. Then, the complete mass spectra of the singly heavy baryons are obtained rigorously, under the mechanism of the heavy-quark dominance. On these bases, the systematical analyses are carried out for the reliability and predictive power of the model, the fine structure of the singly heavy baryon spectra, the assignments of the excited baryons, and some important topics about the heavy baryon spectroscopy such as the missing states, the 'spin-orbit puzzle', the clustering effect, etc. The result confirms that under the heavy-quark dominance mechanism, the relativized quark model can describe the excitation spectra and the fine structures of the singly heavy baryons correctly and precisely.
Published:
Abstract:
Medium modifications of theγ-triggered jets are investigated with the Linear Boltzmann Transport (LBT) model in heavy-ion collisions with varying system sizes, focusing on centrality dependence in Pb+Pb and Xe+Xe collisions at the LHC. Our numerical results reveal that jets produced in central collisions exhibit a wider transverse asymmetry (
\begin{document}$ A_N^y $\end{document}
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) distribution, a broader jet shape, and a more pronouncedγ-jet transverse momentum imbalance (
\begin{document}$ X_{J\gamma}=p_T^{\rm jet}/p_T^\gamma $\end{document}
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) compared to peripheral collisions. These effects arise from the longer path length and stronger jet-medium interactions in central collisions, leading to enhanced jet quenching and medium response. Our findings demonstrate that the magnitude ofγ-jet modifications is sensitive to the size and centrality of the collision system, with larger systems inducing more significant alterations due to increased energy loss and medium feedback.
Medium modifications of theγ-triggered jets are investigated with the Linear Boltzmann Transport (LBT) model in heavy-ion collisions with varying system sizes, focusing on centrality dependence in Pb+Pb and Xe+Xe collisions at the LHC. Our numerical results reveal that jets produced in central collisions exhibit a wider transverse asymmetry (
Published:
Abstract:
Motivated by the first observation of
\begin{document}$ CP $\end{document}
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violation in baryon decays, we study the topological amplitudes of bottom baryon decays in the
\begin{document}$ S U(3)_F $\end{document}
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limit. The topological diagrams of charmless two-body decays of bottom baryons are presented in detail. The linear relations between topologies and
\begin{document}$ S U(3) $\end{document}
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irreducible amplitudes are derived through tensor contraction and
\begin{document}$ S U(3) $\end{document}
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decomposition. Four amplitudes among the thirteen independent amplitudes are critical to the
\begin{document}$ CP $\end{document}
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asymmetries. The small
\begin{document}$ CP $\end{document}
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asymmetries might indicate small relative strong phases between amplitudes
\begin{document}$ A_2 $\end{document}
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and
\begin{document}$ A_{12,14}^\prime $\end{document}
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. To avoid them, we suggest measuring
\begin{document}$ CP $\end{document}
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asymmetries in the
\begin{document}$ \Xi^0_b\to pK^- $\end{document}
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and
\begin{document}$ \Xi^-_b\to \Lambda^0 K^- $\end{document}
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decays. Furthermore, the Körner-Pati-Woo theorem can be tested by measuring the branching fractions of the
\begin{document}$ \Lambda_b^0\to\Sigma^0K^0_S $\end{document}
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and
\begin{document}$ \Lambda_b^0\to\Sigma^-K^+ $\end{document}
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modes.
Motivated by the first observation of
Published:
Abstract:
In this paper, we focus on the gravitational waves emitted by a stellar-mass object in a quasi-circular inspiral orbit around a central supermassive polymerized black hole in loop quantum gravity. Treating the stellar-mass object as a massive test particle, we derive its equations of motion and the corresponding radial effective potential. We find that the peak of the radial effective potential decreases with the quantum parameter
\begin{document}$ \hat{k} $\end{document}
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. We also examine the impact of quantum corrections on the properties of stable circular orbits around the polymerized black hole. We model the smaller object's trajectory as an adiabatic evolution along stable circular orbits using a semi-relativistic approach. In this method, the motion of the object is described by relativistic geodesics, and changes in the object's energy and orbital angular momentum due to gravitational radiation are calculated using the mass quadrupole formula. The corresponding gravitational waveforms are generated using the numerical kludge method, revealing that quantum corrections cause phase advances in the gravitational waveforms. We further analyze the potential constraints on the quantum parameter
\begin{document}$ \hat{k} $\end{document}
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from future space-based gravitational wave observations, concluding that these observations will likely impose stronger constraints on
\begin{document}$ \hat{k} $\end{document}
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than those obtained from black hole shadow measurements.
In this paper, we focus on the gravitational waves emitted by a stellar-mass object in a quasi-circular inspiral orbit around a central supermassive polymerized black hole in loop quantum gravity. Treating the stellar-mass object as a massive test particle, we derive its equations of motion and the corresponding radial effective potential. We find that the peak of the radial effective potential decreases with the quantum parameter
Published:
Abstract:
The event-by-event fluctuations in the initial energy density of the nuclear collisions lead to the decorrelation of second order flow vector, as known as its transverse-momentum (
\begin{document}$ p_{\mathrm{T}} $\end{document}
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) and pseudorapidity (η) dependence as observed in high-energy heavy-ion collisions. Existing measurements at the CERN Large Hadron Collider shown that these decorrelations are also observed in small collision systems. In this work, a systematic study of the transverse-momentum- and pseudorapidity-dependent flow vector decorrelation is performed in p–Pb collisions at the 5.02 TeV with A Multi-Phase Transport (AMPT) model using different tunings of the initial conditions, partonic and hadronic interactions. It is found that the string-melting version of the AMPT model provides a reasonable description of the measured flow vector decorrelation as a function of
\begin{document}$ p_{\mathrm{T}} $\end{document}
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andη. We demonstrate that the hadronic scatterings do not have significant impact on decorrelation in p–Pb collisions for different centrality selections, while both initial conditions and partonic interactions influence the magnitude of the decorrelations. In addition, we found that the subtraction of the nonflow, especially the long-range jet correlation, is crucial for the accurate extraction of the flow vector decorrelation in small collision systems. The comparison of data and model presented in this paper provide further insights in understanding the fluctuations of the flow vector with
\begin{document}$ p_{\mathrm{T}} $\end{document}
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andηin small collision systems and has referential value for future measurements.
The event-by-event fluctuations in the initial energy density of the nuclear collisions lead to the decorrelation of second order flow vector, as known as its transverse-momentum (
Published:
Abstract:
Inspired by the latest experimental progress, we systematically study the Okubo-Zweig-Iizuka(OZI)-allowed two-body strong decay properties of 1P-, 1D-, 2S- and 2P-wave
\begin{document}$ \Lambda_c $\end{document}
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baryons within thej-jcoupling scheme in the framework of the quark pair creation model. The calculations indicate that: (i) Taking the observed states
\begin{document}$ \Lambda_c(2595)^+ $\end{document}
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and
\begin{document}$ \Lambda_c(2625)^+ $\end{document}
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as the 1P-waveλ-modes states
\begin{document}$ \Lambda_c|J^P=1/2^-,1\rangle_{\lambda} $\end{document}
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and
\begin{document}$ \Lambda_c|J^P=3/2^-,1\rangle_{\lambda} $\end{document}
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, respectively, we can reproduce the experimental data well in theory. (ii) Combining with the measured mass and the decay properties of
\begin{document}$ \Lambda_c(2860)^+ $\end{document}
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, this excited state can be explained as 1D-waveλ-mode state
\begin{document}$ \Lambda_c|J^P=3/2^+,1\rangle_{\lambda\lambda} $\end{document}
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. (iii) The newly observed state
\begin{document}$ \Lambda_c(2910)^+ $\end{document}
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may be assigned as one of the 1P-waveρ-mode states
\begin{document}$ \Lambda_c|J^P=3/2^-,2\rangle_{\rho} $\end{document}
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or
\begin{document}$ \Lambda_c|J^P=5/2^-,2\rangle_{\rho} $\end{document}
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. Meanwhile, we notice that the partial decay width ratio between
\begin{document}$ \Sigma_c\pi $\end{document}
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and
\begin{document}$ \Sigma_c^*\pi $\end{document}
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for the two candidates is significantly different. Hence, experimental progress in this ratio measurement may shed light on the nature of
\begin{document}$ \Lambda_c(2910)^+ $\end{document}
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. (iv) According to the properties of
\begin{document}$ \Lambda_c(2765)^+ $\end{document}
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, we find that the 2S-waveλ-mode state
\begin{document}$ \Lambda_{c1}|J^P=1/2^+,0\rangle_{\lambda} $\end{document}
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may be a potential candidate. (v) The 2P-waveλ-mode state
\begin{document}$ \Lambda_{c1}|J^P=3/2^-,1\rangle_{\lambda} $\end{document}
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is mostly likely to be a good assignment of the controversial state
\begin{document}$ \Lambda_c(2940)^+ $\end{document}
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. Both the total decay width and partial decay ratio between
\begin{document}$ pD^0 $\end{document}
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and
\begin{document}$ \Sigma_c\pi $\end{document}
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are in good agreement with the observations. (vi) In addition, for the missing
\begin{document}$ \Lambda_c $\end{document}
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excitations, we obtain their strong decay properties and hope that's useful for future experimental exploration.
Inspired by the latest experimental progress, we systematically study the Okubo-Zweig-Iizuka(OZI)-allowed two-body strong decay properties of 1P-, 1D-, 2S- and 2P-wave
Published:
Abstract:
We introduce a novel level crossing phenomenon in the mass mixing between the QCD axions, one canonical QCD axion and one
\begin{document}$ Z_{{\cal{N}}} $\end{document}
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axion. The level crossing can take place at or slightly before the QCD phase transition critical temperature, depending on the ratio of the axion decay constants
\begin{document}$ \sim 1.69 $\end{document}
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. The cosmological evolution of the mass eigenvalues in these two scenarios is similar; however, the transition of axion energy density differs significantly. Finally, we estimate the relic density of the QCD axion dark matter in this context. Additionally, this level crossing may have some interesting cosmological implications.
We introduce a novel level crossing phenomenon in the mass mixing between the QCD axions, one canonical QCD axion and one
Published:
Abstract:
We show that the traditional moments approach in lattice QCD, based on operator product expansion (OPE), can be realized in a way that utilizes derivatives in momentum rather than in distance. This also avoids power divergent mixings, and thus allows to extract moments order by order, to all orders in principle. Moreover, by exploiting the symmetry of lattice matrix elements, we can determine the even and odd moments separately. As a demonstrative example, we determine the first three moments beyond the tensor charge
\begin{document}$ g_T$\end{document}
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of the isovector quark transversity distribution in the nucleon.
We show that the traditional moments approach in lattice QCD, based on operator product expansion (OPE), can be realized in a way that utilizes derivatives in momentum rather than in distance. This also avoids power divergent mixings, and thus allows to extract moments order by order, to all orders in principle. Moreover, by exploiting the symmetry of lattice matrix elements, we can determine the even and odd moments separately. As a demonstrative example, we determine the first three moments beyond the tensor charge
Published:
Abstract:
The concept “SU(3) analysis” for the B(E2) anomaly is proposed based on various mechanisms found recently, in which the B(E2) anomaly is discussed in the SU(3) symmetry limit. From the results of the analysis, the SU(3) third-order interaction
\begin{document}$ [L\times Q \times L]^{(0)} $\end{document}
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can generate the level-crossing phenomenon for any mechanism, which is vital for the emergence of the B(E2) anomaly. Thus the B(E2) anomaly is found to be related with the SU(3) symmetry. The B(E2) anomaly in
\begin{document}$ ^{^{168}} {\rm{Os}}$\end{document}
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is also discussed.
The concept “SU(3) analysis” for the B(E2) anomaly is proposed based on various mechanisms found recently, in which the B(E2) anomaly is discussed in the SU(3) symmetry limit. From the results of the analysis, the SU(3) third-order interaction
Published:
Abstract:
The study of extra charged gauge boson beyond the Standard Model has always been of great interest. Future muon colliders will have a significant advantage in discovering exotic particles. In this paper, by studying the
\begin{document}$ \mu^+ \mu^- \to W^{\prime +} W^{\prime -} \to e^+ e^- n_e \bar{n}_e $\end{document}
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process, we explore the properties of
\begin{document}$ W^\prime $\end{document}
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in the alternative left-right model. The cross section and angular distribution of the final electron are investigated in the scenario of different
\begin{document}$ W^\prime $\end{document}
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mass and right-handed coupling constant. The forward-backward asymmetry is also an important observable to reflect the properties of
\begin{document}$ W^\prime $\end{document}
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. We provide a method to effectively suppress the background processes by imposing constraints on the transverse momentum
\begin{document}$ P_T $\end{document}
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and azimuthal angle of the final-state electronsα. With the cuts of
\begin{document}$ 600
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GeV and
\begin{document}$ 0.5<\alpha<3 $\end{document}
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, the significance can beyond 5σfor 4.8 TeV
\begin{document}$ W^\prime $\end{document}
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at the collision energy of 10 TeV.
The study of extra charged gauge boson beyond the Standard Model has always been of great interest. Future muon colliders will have a significant advantage in discovering exotic particles. In this paper, by studying the
Published:
Abstract:
Based on the dinuclear system model, the effects of the capture, fusion, and survival stages on the fusion-evaporation reactions have been analyzed. The calculated evaporation residue cross sections achieve good agreements with current experimental data. The reactions Ar+Fm are promising for synthesizing Oganesson isotopes mainly due to the lower internal fusion barriers, leading to a higher fusion probabilities. New isotopes
\begin{document}$ ^{287-290}\text{Og}$\end{document}
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can be synthesized through the reactions
\begin{document}$ ^{254}\text{Fm}(^{36}\text{Ar}, 3{\text{n}})^{287}\text{Og}$\end{document}
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,
\begin{document}$ ^{255}\text{Fm}(^{36}\text{Ar}, 3{\text{n}})^{288}\text{Og}$\end{document}
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,
\begin{document}$ ^{254}\text{Fm}(^{38}\text{Ar}, 3{\text{n}})^{289}\text{Og}$\end{document}
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, and
\begin{document}$ ^{257}\text{Fm}(^{36}\text{Ar}, 3{\text{n}})^{290}\text{Og}$\end{document}
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, respectively. The corresponding maximum evaporation residue cross sections are 16.4 pb, 65.1 pb, 12.4 pb, and 111.1 pb, respectively.
Based on the dinuclear system model, the effects of the capture, fusion, and survival stages on the fusion-evaporation reactions have been analyzed. The calculated evaporation residue cross sections achieve good agreements with current experimental data. The reactions Ar+Fm are promising for synthesizing Oganesson isotopes mainly due to the lower internal fusion barriers, leading to a higher fusion probabilities. New isotopes
Published:
Abstract:
When the spins of deuteron and triton are aligned in parallel, the fusion cross-section increases by about 50%. The emitted neutrons are anisotropic and polarized in specific directions. The polarized neutron beams can be used to measure strong magnetic fields in high energy density plasmas, offering a potential alternative to the well-established proton imaging technique. In contrast to protons, neutrons are not deflected by electromagnetic fields and are not sensitive to electric fields, thus reducing the complexity of magnetic field reconstruction. Three-dimensional spin transport hydrodynamics simulations are employed to investigate the polarized neutron beams generated from spin-polarized deuterium-tritium target implosions. Synthetic polarized neutron images of magnetic fields are generated from Monte Carlo simulations. By comparing the results of finite-size sources and ideal point source, a method to compensate the finite-source-size blurring effect is proposed to reduce the error in magnetic field reconstruction.
When the spins of deuteron and triton are aligned in parallel, the fusion cross-section increases by about 50%. The emitted neutrons are anisotropic and polarized in specific directions. The polarized neutron beams can be used to measure strong magnetic fields in high energy density plasmas, offering a potential alternative to the well-established proton imaging technique. In contrast to protons, neutrons are not deflected by electromagnetic fields and are not sensitive to electric fields, thus reducing the complexity of magnetic field reconstruction. Three-dimensional spin transport hydrodynamics simulations are employed to investigate the polarized neutron beams generated from spin-polarized deuterium-tritium target implosions. Synthetic polarized neutron images of magnetic fields are generated from Monte Carlo simulations. By comparing the results of finite-size sources and ideal point source, a method to compensate the finite-source-size blurring effect is proposed to reduce the error in magnetic field reconstruction.
Published:
Abstract:
In this work, we apply the effective Lagrangian approach to investigate the two-body strong decay behaviors of the possible
\begin{document}$ \Lambda_c K^* $\end{document}
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and
\begin{document}$ \Sigma_c K^{(*)} $\end{document}
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molecules, as predicted in our previous study [Phys. Rev. D108, 054011 (2023)]. Our results indicate that the decay width for the coupled
\begin{document}$ \Sigma_c K / \Lambda_c K^* / \Sigma_c K^* $\end{document}
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molecule with
\begin{document}$ I(J^P) = 1/2(1/2^-) $\end{document}
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is on the order of several MeV, with the
\begin{document}$ D_s N $\end{document}
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channel being dominant. For the coupled
\begin{document}$ \Lambda_c K^* / \Sigma_c K^* $\end{document}
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molecule with
\begin{document}$ 1/2(1/2^-, 3/2^-) $\end{document}
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, the decay widths are on the order of tens of MeV, with the dominant channels being
\begin{document}$ \Sigma_c K $\end{document}
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and
\begin{document}$ \Sigma_c^* K $\end{document}
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, respectively. For the
\begin{document}$ \Sigma_c K^* $\end{document}
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molecules with
\begin{document}$ 1/2(1/2^-) $\end{document}
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, the decay width can reach one hundred MeV, with
\begin{document}$ \Sigma_c K $\end{document}
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and
\begin{document}$ \Lambda_c K $\end{document}
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being the dominant decay channels. The decay widths for the
\begin{document}$ \Sigma_c K^* $\end{document}
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molecules with
\begin{document}$ 1/2(3/2^-) $\end{document}
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and
\begin{document}$ 3/2(1/2^-) $\end{document}
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are on the order of tens of MeV, with the dominant decay modes being
\begin{document}$ \Sigma_c^* K $\end{document}
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and
\begin{document}$ \Sigma_c K $\end{document}
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, respectively. The branching ratios for all the discussed channels show little dependence on the binding energies.
In this work, we apply the effective Lagrangian approach to investigate the two-body strong decay behaviors of the possible
Published:
Abstract:
We use a modified relativistic quark model to study the properties of excited charmed and charmed strange mesons. We calculate the masses and wave functions of conventional charmed and charmed strange mesons incorporating both spin andS-Dmixing effects and fit parameters of the potential model with known experimental states using differential evolution technique. Using Leading Born-Oppenheimer expansion, we also compute the spectrum and wave functions of first gluonic excited state of charmed and charmed strange mesons. We examine the effects of gluonic excitation on the spectrum of resultant hybrid mesons. By using our calculated spectrum and wave functions, we determine the radiative transitions of the conventional and hybrid open charm mesons. We compare our calculations with experimental data and other works. We expect our results will be beneficial in the detection of the charmed and charmed strange conventional and hybrids mesons.
We use a modified relativistic quark model to study the properties of excited charmed and charmed strange mesons. We calculate the masses and wave functions of conventional charmed and charmed strange mesons incorporating both spin andS-Dmixing effects and fit parameters of the potential model with known experimental states using differential evolution technique. Using Leading Born-Oppenheimer expansion, we also compute the spectrum and wave functions of first gluonic excited state of charmed and charmed strange mesons. We examine the effects of gluonic excitation on the spectrum of resultant hybrid mesons. By using our calculated spectrum and wave functions, we determine the radiative transitions of the conventional and hybrid open charm mesons. We compare our calculations with experimental data and other works. We expect our results will be beneficial in the detection of the charmed and charmed strange conventional and hybrids mesons.
Published:
Abstract:
Within the framework of the next to the minimal supersymmetric (SUSY) extension of the Standard Model (SM) with a local B-L gauge symmetry (N-B-LSSM), we study lepton flavor violating (LFV)
\begin{document}$ \tau\rightarrow e M^+ M^- $\end{document}
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decays:
\begin{document}$ \tau \rightarrow e \pi^+\pi^- $\end{document}
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,
\begin{document}$ \tau \rightarrow e \pi^+K^- $\end{document}
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,
\begin{document}$ \tau \rightarrow e K^+K^- $\end{document}
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. According to the latest experimental data, the influence of different sensitive parameters on the branching ratios is considered. It can be seen from the numerical analysis that the main sensitive parameters and LFV sources are non-diagonal elements corresponding to the initial and final leptons. This work can provide a basis for discovering the existence of new physics (NP).
Within the framework of the next to the minimal supersymmetric (SUSY) extension of the Standard Model (SM) with a local B-L gauge symmetry (N-B-LSSM), we study lepton flavor violating (LFV)
Published:
Abstract:
The lepton number violation decay
\begin{document}$ \omega \to \pi^+ \pi^+ e^-e^- +c.c. $\end{document}
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is searched for via
\begin{document}$ J/\psi \to \omega\eta $\end{document}
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using a data sample of
\begin{document}$ (1.0087 \pm 0.0044) \times 10^{10} $\end{document}
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\begin{document}$ J/\psi $\end{document}
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events collected by the BESIII detector at the BEPCII collider. No significant signal is observed, and the upper limit on the branching fraction of
\begin{document}$ \omega \to \pi^+ \pi^+ e^-e^- +c.c. $\end{document}
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at the 90% confidence level is determined for the first time to be
\begin{document}$ 2.8 \times 10^{-6} $\end{document}
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.
The lepton number violation decay
Published:
Abstract:
The signature splitting observed in 3/2[521]ν↑
\begin{document}$\otimes $\end{document}
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1/2[660]ν↑
\begin{document}$\otimes $\end{document}
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1/2[660]ν↑ three-quasineutron rotational band of155Dy is examined within the framework of axially symmetric three-quasiparticle plus axially symmetric rotor model. The experimental level energies as well as the magnitude of observed splitting is well reproduced with RMS deviation of 68.13 keV and 0.58 keV respectively. The major contributing bands in the observed splitting are Kπ=7/2-:5/2[512]ν↑
\begin{document}$\otimes $\end{document}
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3/2[651]ν↑
\begin{document}$\otimes $\end{document}
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1/2[660]ν↓, Kπ=5/2-: 5/2[512]ν↑
\begin{document}$\otimes $\end{document}
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3/2[651]ν↑
\begin{document}$\otimes $\end{document}
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3/2[651]ν↓, Kπ=1/2-:3/2[521]ν↑
\begin{document}$\otimes $\end{document}
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1/2[660]ν↑
\begin{document}$\otimes $\end{document}
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3/2[651]ν↓, Kπ=1/2-: 3/2[521]ν↓
\begin{document}$\otimes $\end{document}
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1/2[660]ν↑
\begin{document}$\otimes $\end{document}
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3/2[651]ν↑, Kπ=5/2-:3/2[521]ν↑
\begin{document}$\otimes $\end{document}
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3/2[651]ν↑
\begin{document}$\otimes $\end{document}
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1/2[660]ν↓, and Kπ=3/2-: 3/2[521]ν↑
\begin{document}$\otimes $\end{document}
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3/2[651]ν↑
\begin{document}$\otimes $\end{document}
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3/2[651]ν↓ which mix through rotor-particle (ΔK=1) and particle-particle (ΔK=0) couplings among the bands comprising the given basis space. The observed signature splitting is also well reproduced by the superposition of calculated energy staggering of the strongly interacting bands, which further strengthen the validity of present particle rotor model calculations. Based on the present calculations, we assign the bandhead spin as Kπ= 3/2-to the band under discussion. Additionally, the locations of 13 low-lying band members in the spin range Iπ=3/2-to 23/2-and at 27/2-and 31/2-are predicted, which will be useful for future experimental investigations.
The signature splitting observed in 3/2[521]ν↑
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Abstract:
In this work, under the thin disk model, we examine the optical observational characteristics of asymmetric thin-shell wormholes (ATWs) within the theoretical framework of higher-order non-commutative geometry. By utilizing ray tracing technology, the trajectories of photons under various relevant parameters, as well as the optical observational appearance of ATW, can be accurately simulated. Compared to the black hole (BH) spacetime, observational images of ATW will exhibit additional bright ring structures. The results show that an increase in the non-commutative parameter leads to the innermost extra photon ring moving away from the shadow region, while the second extra photon ring moves closer to the shadow region. However, only one additional bright ring structure is observed in the image when the non-commutative parameter increases toθ= 0.03, which implies that the observed features of ATWs seem to become more and more visually similar to a BH asθincreased. Furthermore, an increase in the mass ratio will result in a reduction of the radius of the innermost extra photon ring, whereas an increase in the throat radius will lead to an expansion of its radius. Notably, neither parameter has a significant impact on the size of the second extra photon ring. These findings significantly advance our theoretical understanding of the optical features of ATWs with higher-order non-commutative corrections.
In this work, under the thin disk model, we examine the optical observational characteristics of asymmetric thin-shell wormholes (ATWs) within the theoretical framework of higher-order non-commutative geometry. By utilizing ray tracing technology, the trajectories of photons under various relevant parameters, as well as the optical observational appearance of ATW, can be accurately simulated. Compared to the black hole (BH) spacetime, observational images of ATW will exhibit additional bright ring structures. The results show that an increase in the non-commutative parameter leads to the innermost extra photon ring moving away from the shadow region, while the second extra photon ring moves closer to the shadow region. However, only one additional bright ring structure is observed in the image when the non-commutative parameter increases toθ= 0.03, which implies that the observed features of ATWs seem to become more and more visually similar to a BH asθincreased. Furthermore, an increase in the mass ratio will result in a reduction of the radius of the innermost extra photon ring, whereas an increase in the throat radius will lead to an expansion of its radius. Notably, neither parameter has a significant impact on the size of the second extra photon ring. These findings significantly advance our theoretical understanding of the optical features of ATWs with higher-order non-commutative corrections.
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Abstract:
Shell effect plays an important role in nuclear mass predictions especially for the nuclei around the magic numbers. In this study, a new semi-empirical shell correction terms is constructed to improve the mass description of the Bethe-Weizsäcker (BW) formula. For nuclei with
\begin{document}$ Z,~N \geqslant 8$\end{document}
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, the root mean square (rms) deviation of the newly proposed formula with respect to the latest nuclear mass evaluation dataset AME2020 is 0.887 MeV, inducing a 72.23% reduction compared to the rms deviation of 3.194 MeV for the BW formula. The deviations between the theoretical predictions and the experimental data are within 1.5 MeV for 91.90% of the nuclei. In addition, the new mass formula significantly improves the predictions of the binding energies for magic nuclei, the rms deviation of our formula for the binding energy of magic nuclei is only 1.065 MeV, which is a 80.80% reduction compared with that of the BW formula.
Shell effect plays an important role in nuclear mass predictions especially for the nuclei around the magic numbers. In this study, a new semi-empirical shell correction terms is constructed to improve the mass description of the Bethe-Weizsäcker (BW) formula. For nuclei with
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Abstract:
The lifetime of the isomeric state in fully stripped94Ru44+ions has been measured using isochronous mass spectrometry (IMS) at the experimental Cooler Storage Ring (CSRe) of the Heavy Ion Research Facility in Lanzhou (HIRFL). Previously, the isomeric lifetime was determined by analyzing the decay time points of individual decay events. In this work, we present a novel approach to determine the isomeric lifetime based on the survival time of ions in the IMS. The survival lifetime of the ground and isomeric states of94Ru44+were measured to be
\begin{document}$ 270(9)\,\mu $\end{document}
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s and
\begin{document}$ 121(4)\,\mu $\end{document}
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s in the laboratory frame, respectively. Given that the ground state of94Ru44+has a natural lifetime of approximately 75 minutes, its survival lifetime in the experimental setup was predominantly determined by beam-loss lifetime, including interactions with residual gas in the storage ring and the carbon foil of detector. In contrast, the survival lifetime of the94mRu44+was governed by both its intrinsic nuclear lifetime and additional beam-loss effects. The nuclear decay lifetime of94mRu44+was extracted through differential survival lifetime analysis between ground and isomeric state, under the assumption that the beam-loss lifetimes for both quantum systems are identical. Using this novel methodology, the laboratory-frame lifetime measurement yielded
\begin{document}$ 221(14)\,\mu $\end{document}
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s. After relativistic time-dilation corrections, the corresponding rest-frame half-life was calculated to be
\begin{document}$ 118(7)\,\mu $\end{document}
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s. This result demonstrates excellent consistency with previous experimental results, validating the reliability of the new method. This method is suitable for determining half-lives of highly-charged ions in the range of about several tens of microsecond to milliseconds using IMS.
The lifetime of the isomeric state in fully stripped94Ru44+ions has been measured using isochronous mass spectrometry (IMS) at the experimental Cooler Storage Ring (CSRe) of the Heavy Ion Research Facility in Lanzhou (HIRFL). Previously, the isomeric lifetime was determined by analyzing the decay time points of individual decay events. In this work, we present a novel approach to determine the isomeric lifetime based on the survival time of ions in the IMS. The survival lifetime of the ground and isomeric states of94Ru44+were measured to be
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Abstract:
The 21-cm forest offers a powerful cosmological probe of the thermal history and small-scale structure of the intergalactic medium during the Epoch of Reionization (EoR). Its success, however, critically depends on the availability of high-redshift radio-loud quasars (HzRLQs) as background sources. In this work, we investigate the configuration requirements for a Moon-based low-frequency radio interferometer aimed at maximizing the detection of HzRLQs for future 21-cm forest studies. Building upon a previously developed quasar luminosity function (QLF), we forecast HzRLQ abundances under various array configurations. Assuming a total survey area of
\begin{document}$ 10^4\,\mathrm{deg}^2 $\end{document}
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and 1 year of observation, we compare continuum surveys with 10 MHz bandwidth and 21-cm forest surveys with 5 kHz resolution. Our results show that a minimum collecting area of ~6 500 m2enables detection at
\begin{document}$ z \sim 6 $\end{document}
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, while SKA-like arrays (
\begin{document}$ N_{\mathrm{st}} = 512 $\end{document}
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) extend the detection limit to
\begin{document}$ z \sim 10 $\end{document}
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for 21-cm forest survey and
\begin{document}$ z \sim 16 $\end{document}
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for continuum survey. Larger arrays with
\begin{document}$ N_{\mathrm{st}} = 2048 $\end{document}
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can reach
\begin{document}$ z \sim 11 $\end{document}
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in 21-cm forest mode. We also explore configurations that maintain fixed collecting areas while increasing the number to enhance survey efficiency. This boosts source detection but significantly increases the data volume and computational demands. These results underscore the importance of optimizing array design for different survey goals and balancing sensitivity, spectral resolution, and data management. A well-designed Moon-based array could open a new observational window on reionization and early cosmic structure formation.
The 21-cm forest offers a powerful cosmological probe of the thermal history and small-scale structure of the intergalactic medium during the Epoch of Reionization (EoR). Its success, however, critically depends on the availability of high-redshift radio-loud quasars (HzRLQs) as background sources. In this work, we investigate the configuration requirements for a Moon-based low-frequency radio interferometer aimed at maximizing the detection of HzRLQs for future 21-cm forest studies. Building upon a previously developed quasar luminosity function (QLF), we forecast HzRLQ abundances under various array configurations. Assuming a total survey area of
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Abstract:
In this study, we investigate the electromagnetic properties
\begin{document}$ - $\end{document}
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specifically, the magnetic dipole, electric quadrupole, and magnetic octupole moments
\begin{document}$ - $\end{document}
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of six hidden-charm pentaquark states:
\begin{document}$ [u u][d c] \bar c $\end{document}
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,
\begin{document}$ [dd][u c] \bar c $\end{document}
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,
\begin{document}$ [u u][s c] \bar c $\end{document}
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,
\begin{document}$ [dd] [s c] \bar c $\end{document}
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,
\begin{document}$ [s s][u c] \bar c $\end{document}
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, and
\begin{document}$ [s s][d c] \bar c $\end{document}
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. Employing the framework of QCD light-cone sum rules and utilizing two distinct diquark-diquark-antiquark interpolating currents, we focus on pentaquark configurations with spin-parity quantum numbers
\begin{document}$ {{\rm{J}}^{\rm{P}} = \frac{3}{2}^-} $\end{document}
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. From the numerical results, we observe significant deviations between the magnetic dipole moment predictions obtained using different diquark-diquark-antidiquark structures. These results suggest that multiple pentaquark states with identical quantum numbers and quark constituents may exhibit distinct magnetic dipole moments, depending on their internal quark configurations. The obtained electromagnetic moments, particularly the variations in magnetic dipole moments, may provide insights into the internal structure of hidden-charm pentaquark states.
In this study, we investigate the electromagnetic properties
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This article is devoted to calculating the form factors of
\begin{document}$B_c \to D^{*}$\end{document}
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,
\begin{document}$B_c \to D$\end{document}
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,
\begin{document}$B_c \to D_s^{*}$\end{document}
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and
\begin{document}$B_c \to D_s$\end{document}
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transitions in the framework of three-point QCD sum rules. At the QCD side, the contributions of
\begin{document}$\langle\overline{q}q\rangle$\end{document}
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,
\begin{document}$\langle\overline{q}g_{s}\sigma Gq\rangle$\end{document}
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,
\begin{document}$\langle g_{s}^{2}G^{2}\rangle$\end{document}
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,
\begin{document}$\langle g^{3}f_{abc}G^{3}\rangle$\end{document}
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and
\begin{document}$\langle\overline{q}q\rangle \langle g_{s}^{2}G^{2}\rangle$\end{document}
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are taken into account. With the obtained form factors, the decay widths and branching ratios of several two-body nonleptonic decay processes
\begin{document}$B_c \to \eta_c D^{*}$\end{document}
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,
\begin{document}$\eta_c D$\end{document}
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,
\begin{document}$ J/\psi D^{*}$\end{document}
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,
\begin{document}$ J/\psi D$\end{document}
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,
\begin{document}$\eta_c D_s^{*}$\end{document}
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,
\begin{document}$\eta_c D_s$\end{document}
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,
\begin{document}$J/\psi D_s^{*}$\end{document}
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and
\begin{document}$J/\psi D_s$\end{document}
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are predicted. These results about the form factors and decay properties of
\begin{document}$B_c$\end{document}
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meson provide useful information for us to study the heavy-quark dynamical behavior.
This article is devoted to calculating the form factors of
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Abstract:
We developed a time-of-flight (TOF) detector with a thin foil for mass measurements of unstable nuclei using the Rare-RI Ring at the RIKEN RI beam factory. Compared to the previous design, the TOF detector's electrodes were modified, and its static electric and magnetic fields were reduced. We improved the detection efficiency and the stability of the operation. Its specification and design were finally fixed for mass measurements. We also developed a position-sensitive detector based on the principle of the TOF detector. In the present study, large microchannel plate (MCP) detectors were used compared to those of the prototype. By improving the acceptance, we demonstrated the performances of the position-sensitive detector with a very low material thickness.
We developed a time-of-flight (TOF) detector with a thin foil for mass measurements of unstable nuclei using the Rare-RI Ring at the RIKEN RI beam factory. Compared to the previous design, the TOF detector's electrodes were modified, and its static electric and magnetic fields were reduced. We improved the detection efficiency and the stability of the operation. Its specification and design were finally fixed for mass measurements. We also developed a position-sensitive detector based on the principle of the TOF detector. In the present study, large microchannel plate (MCP) detectors were used compared to those of the prototype. By improving the acceptance, we demonstrated the performances of the position-sensitive detector with a very low material thickness.
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This paper uses the gravitational decoupling method (GD) via minimal geometric deformation (MGD) to discuss the understanding of strange deformed stars (SS) in modified
\begin{document}$ f({\cal{T}}) $\end{document}
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gravity theory. By adopting the Buchdahl ansatz and the quadratic polytropic equation of state (EOS), we derive deformed SS models by assuming that the energy-momentum components of the deformed fluid obey
\begin{document}$ \rho=\Theta_0^0 $\end{document}
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and
\begin{document}$ p_r=\Theta_1^1 $\end{document}
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. This approach leads to different classes of exact solutions. The study of physical viability tests ensures that the proposed configurations adhere to realistic constraints. Furthermore, the impact of relevant parameters is analyzed for the three scenarios: GR,
\begin{document}$ f({\cal{T}}) $\end{document}
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, and
\begin{document}$ f({\cal{T}})+MGD $\end{document}
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. In addition, observational constraints are used to make comparisons, including GW190814, neutron stars (NSTRs) PSR J1614-2230, and PSR J1903 + 327, with mass ranges of
\begin{document}$ 2.5-2.67 M_\odot $\end{document}
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,
\begin{document}$ 1.97 \pm 0.04 M_\odot $\end{document}
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, and
\begin{document}$ 1.667 \pm 0.021\; M_\odot $\end{document}
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, respectively. Remarkably, we observe from the
\begin{document}$ M-R $\end{document}
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curves that NSTRs with masses ranging from
\begin{document}$ 2.4 $\end{document}
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to
\begin{document}$ 3.5M_{\odot} $\end{document}
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correspond to a range of radii from
\begin{document}$ 9.80^{+0.02}_{-0.01} $\end{document}
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to
\begin{document}$ 13.01^{+0.01}_{-0.01}km $\end{document}
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for different values of the parametersα,β,γand
\begin{document}$ \zeta_1 $\end{document}
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. Interestingly, for the
\begin{document}$ \rho=\Theta_0^0 $\end{document}
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solution, higher values ofαproduce NSTRs with smaller masses and smaller radii, while the
\begin{document}$ p_r=\Theta_1^1 $\end{document}
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solution gives larger masses and larger radii, which supports the existence of massive NSTRs within modified gravity theory
\begin{document}$ f({\cal{T}}) $\end{document}
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.
This paper uses the gravitational decoupling method (GD) via minimal geometric deformation (MGD) to discuss the understanding of strange deformed stars (SS) in modified
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Abstract:
The size of the direct CP asymmetry generated during the weak decay of hadrons is attributed to the weak phase and some strong phases. The weak phase comes from the CKM matrix and a strong phase may result from the resonance effect which is produced by the mixing of vector meson
\begin{document}$ V\left\{\rho^{0}(770),\omega(782),\phi(1020)\right\} $\end{document}
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to
\begin{document}$ \pi^+ \pi^- $\end{document}
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meson pairs.
\begin{document}$ \rho^{0}(770) $\end{document}
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can decay directly into
\begin{document}$ \pi^+ \pi^- $\end{document}
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meson pairs, both
\begin{document}$ \omega(782) $\end{document}
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and
\begin{document}$ \phi(1020) $\end{document}
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can also decay into
\begin{document}$ \pi^+ \pi^- $\end{document}
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meson pairs with small contribution from isospin symmetry breaking. The main contribution for the middle state vector meson
\begin{document}$ \rho^{0}(770)-\omega(782)-\phi(1020) $\end{document}
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interference is the mix of
\begin{document}$ \rho^{0}(770) $\end{document}
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,
\begin{document}$ \omega(782)-\rho^{0}(770) $\end{document}
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and
\begin{document}$ \phi(1020)-\rho^{0}(770) $\end{document}
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. We calculate the CP asymmetry and decay branching ratio for
\begin{document}$ \bar{B}^0_{s} \rightarrow \pi^+ \pi^- \pi^0 (\bar K ^{0}) $\end{document}
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in the framework of QCD factorization and compare them with previous work. We also add the analysis of
\begin{document}$ \bar{B}^0_{s} \rightarrow \pi^+ \pi^- \eta(\eta^{(')}) $\end{document}
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decay process. The results show that the CP asymmetry of these four decay processes are significantly enhanced especially for the
\begin{document}$ \bar{B}^0_{s} \rightarrow \pi^+ \pi^- \bar K ^{0} $\end{document}
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decay process and the decay branching ratio also changes under resonance effect. These work might provide support for the experimental analysis of the
\begin{document}$ \bar B^{0}_s $\end{document}
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meson.
The size of the direct CP asymmetry generated during the weak decay of hadrons is attributed to the weak phase and some strong phases. The weak phase comes from the CKM matrix and a strong phase may result from the resonance effect which is produced by the mixing of vector meson
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Abstract:
We study the properties of the outer crust of nonaccreting cold neutron stars employing a liquid-drop model based on a microscopic Brueckner-Hartree-Fock energy-density functional. We compute the extended nuclear mass table, especially close to the neutron dripline. Combined with the latest experimental binding energies AME2020, we obtain the sequence of the equilibrium nuclei and construct the equation of state for the outer crust. Various properties of the outer crust are calculated in detail and compared with other crust models.
We study the properties of the outer crust of nonaccreting cold neutron stars employing a liquid-drop model based on a microscopic Brueckner-Hartree-Fock energy-density functional. We compute the extended nuclear mass table, especially close to the neutron dripline. Combined with the latest experimental binding energies AME2020, we obtain the sequence of the equilibrium nuclei and construct the equation of state for the outer crust. Various properties of the outer crust are calculated in detail and compared with other crust models.
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Gravity is identical to curved spacetime. It is manifested by the curvature of a Riemannian spacetime in general relativity but by torsion or non-metricity in teleparallel gravity models. In this paper, we apply these multiple options to the spacetime perturbation theory and seek the possibilities of representing the gravitation of the background and that of the perturbation in separate ways. We show that the perturbation around a Riemannian background can be described by torsion or non-metricity, so that we have teleparallel like actions for the perturbation.
Gravity is identical to curved spacetime. It is manifested by the curvature of a Riemannian spacetime in general relativity but by torsion or non-metricity in teleparallel gravity models. In this paper, we apply these multiple options to the spacetime perturbation theory and seek the possibilities of representing the gravitation of the background and that of the perturbation in separate ways. We show that the perturbation around a Riemannian background can be described by torsion or non-metricity, so that we have teleparallel like actions for the perturbation.
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Abstract:
In this work, we perform a cosmological-model-independent test on the cosmic distance duality relation (CDDR) by comparing the angular diameter distance (ADD) obtained from the compact radio quasars (QSOs) with the luminosity distance (LD) from the Pantheon+ Type Ia supernovae (SNIa) sample. The binning method and Artificial Neural Network (ANN) are employed to match ADD data with LD data at the same redshift, and three different parameterizations are adopted to quantify the possible deviations from the CDDR. We initially investigate the impacts of the specific prior values for the absolute magnitude
\begin{document}$ M_{\rm{B}} $\end{document}
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from SNIa and the linear size scaling factorlfrom QSOs on the CDDR test, demonstrating that these prior values introduce significant biases in the CDDR test. To avoid the biases, we propose a method independent of
\begin{document}$ M_{\rm{B}} $\end{document}
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andlto test CDDR, which treats the fiducial value of a new variable
\begin{document}$ \kappa\equiv 10^{M_{\rm{B}} \over 5}\,l $\end{document}
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as a nuisance parameter and then marginalize its impact with a flat prior in the statistical analysis. The results show that the CDDR is consistent with the observational data, and QSOs can serve as a powerful tool for testing the CDDR independent of cosmological models.
In this work, we perform a cosmological-model-independent test on the cosmic distance duality relation (CDDR) by comparing the angular diameter distance (ADD) obtained from the compact radio quasars (QSOs) with the luminosity distance (LD) from the Pantheon+ Type Ia supernovae (SNIa) sample. The binning method and Artificial Neural Network (ANN) are employed to match ADD data with LD data at the same redshift, and three different parameterizations are adopted to quantify the possible deviations from the CDDR. We initially investigate the impacts of the specific prior values for the absolute magnitude
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Abstract:
The study investigated the elastic and inelastic scattering of3He particles from12C,16O,24Mg, and28Si nuclei at 60 MeV using a double-folding approach with four newly derived effective nucleon-nucleon interactions (R3Y(HS), R3Y(L1), R3Y(W), and R3Y(Z)) derived from the relativistic mean-field (RMF) theory. The four derived effective NN interactions exhibited strong sensitivity to the choice of exchange potential. Regularizing NN interactions improved the agreement between calculated folded potentials and experimental data. Normalization constants for the R3Y(HS) interaction suggest its superiority over the R3Y(L1) and R3Y(W) interactions within the double-folding framework. Transition potentials based on two models, deformed potential and double folding potential, were used to describe inelastic scattering. Physically consistent deformation parameters were obtained. The deformed potential model yielded better results for12C and16O, whereas the double folding model performed better for24Mg and28Si, suggesting the double folding model's advantage is limited for lighter targets. The Bohr-Mottelson transition density effectively described 2+states but was less suitable for the 3−state of16O, for which a Tassie-like transition density provided improved agreement.
The study investigated the elastic and inelastic scattering of3He particles from12C,16O,24Mg, and28Si nuclei at 60 MeV using a double-folding approach with four newly derived effective nucleon-nucleon interactions (R3Y(HS), R3Y(L1), R3Y(W), and R3Y(Z)) derived from the relativistic mean-field (RMF) theory. The four derived effective NN interactions exhibited strong sensitivity to the choice of exchange potential. Regularizing NN interactions improved the agreement between calculated folded potentials and experimental data. Normalization constants for the R3Y(HS) interaction suggest its superiority over the R3Y(L1) and R3Y(W) interactions within the double-folding framework. Transition potentials based on two models, deformed potential and double folding potential, were used to describe inelastic scattering. Physically consistent deformation parameters were obtained. The deformed potential model yielded better results for12C and16O, whereas the double folding model performed better for24Mg and28Si, suggesting the double folding model's advantage is limited for lighter targets. The Bohr-Mottelson transition density effectively described 2+states but was less suitable for the 3−state of16O, for which a Tassie-like transition density provided improved agreement.
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Abstract:
We study the inelastic charmonium (
\begin{document}$ J/\psi $\end{document}
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,
\begin{document}$ \psi(2S) $\end{document}
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) and bottomonium (
\begin{document}$ \Upsilon(nS) $\end{document}
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) photoproduction and fragmentation processes inp-pand
\begin{document}$ Pb $\end{document}
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-
\begin{document}$ Pb $\end{document}
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collisions at LHC energies, where the ultra-incoherent photon emission is included. In the framework of the NRQCD factorization approach, an exact treatment is developed which recovers Weizsäcker-Williams approximation (WWA) near the region
\begin{document}$ Q^{2}\sim0 $\end{document}
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, where the methods of Martin-Ryskin and BCCKL are used to avoid double counting. We calculate the
\begin{document}$ Q^{2} $\end{document}
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,y,z,
\begin{document}$ \sqrt{s} $\end{document}
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,
\begin{document}$ p_{T} $\end{document}
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dependent and the total cross sections. It turns out that the inelastic photoproduction and fragmentation processes provide valuable contributions to the heavy quarkonium production, especially in the large
\begin{document}$ p_{T} $\end{document}
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regions. While the relative contribution of ultra-incoherent photon channel is very important, which rapidly increases along with the growing quarkonium mass, and begins to dominate the photoproduction processes at large
\begin{document}$ p_{T} $\end{document}
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ranges. Moreover, we obtain the complete validity scopes of WWA in inelastic heavy quarkonium photoproduction in heavy-ion collisions. WWA has a much higher accuracy at high energies and in
\begin{document}$ Pb $\end{document}
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-
\begin{document}$ Pb $\end{document}
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collisions. The existing photon spectra are generally derived beyond the applicable scopes of WWA, and the double counting exists when the different channels are considered simultaneously.
We study the inelastic charmonium (
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Abstract:
We present a comprehensive analysis of near-threshold photoproduction of
\begin{document}$\rho^0$\end{document}
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,ω, andϕmesons on a deuterium target, utilizing published datasets from DESY and SLAC for
\begin{document}$\rho^0$\end{document}
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andωproduction, as well as data from the LEPS and CLAS Collaborations forϕproduction. In extracting the deuteron mass radius, we adopt a dipole parametrization for the scalar gravitational form factor, which effectively captures the
\begin{document}$|t|$\end{document}
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-dependence of the differential cross sections associated with vector meson photoproduction. In addition, results from alternative commonly used form factor parametrizations are also considered and compared. Employing the vector meson dominance (VMD) framework and invoking low-energy Quantum Chromodynamics (QCD) theorems, we extract the deuteron mass radius from near-threshold photoproduction data of
\begin{document}$\rho^0$\end{document}
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,ω, andϕmesons. The mass radii obtained from the various datasets are found to be consistent within statistical uncertainties, yielding an average value of
\begin{document}$2.03 \pm 0.13$\end{document}
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fm under the dipole form assumption. We also provide a detailed discussion of the sensitivity of the extracted radius to different choices of gravitational form factor models. Our result represents a significant improvement in precision compared to earlier estimates based solely onϕmeson photoproduction, offering new constraints for theoretical models of nuclear structure and deepening our understanding of the mass distribution within the deuteron.
We present a comprehensive analysis of near-threshold photoproduction of
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Abstract:
Application of the dynamical eikonal approximation(DEA) to elastic scattering for Coulomb-dominated reactions at low energy is studied. Our test case consists of elastic scattering for8B,9C and11Be on208Pb at 21.3, 25.2 and 12.7 MeV/nucleon, respectively. We introduce an empirical correction to the DEA method to account for Coulomb deflection, which significantly improves the description of elastic scattering of weakly-bound nuclei on heavy target. The angular distributions of elastic scattering obtained using the empirical correction show a good agreement with experimental data down to around 10 MeV/nucleon. Furthermore, we study the the effect of relativistic kinematics corrections on the angular distributions of elastic scattering at incident energies between 20 and 60 MeV/nucleon. The results show that relativistic kinematics corrections are crucial for describing the angular distributions of elastic scattering as low as around 40 MeV/nucleon.
Application of the dynamical eikonal approximation(DEA) to elastic scattering for Coulomb-dominated reactions at low energy is studied. Our test case consists of elastic scattering for8B,9C and11Be on208Pb at 21.3, 25.2 and 12.7 MeV/nucleon, respectively. We introduce an empirical correction to the DEA method to account for Coulomb deflection, which significantly improves the description of elastic scattering of weakly-bound nuclei on heavy target. The angular distributions of elastic scattering obtained using the empirical correction show a good agreement with experimental data down to around 10 MeV/nucleon. Furthermore, we study the the effect of relativistic kinematics corrections on the angular distributions of elastic scattering at incident energies between 20 and 60 MeV/nucleon. The results show that relativistic kinematics corrections are crucial for describing the angular distributions of elastic scattering as low as around 40 MeV/nucleon.
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In recent years, many studies on neutrino-nucleus scattering have been carried out to investigate nuclear structures and the interactions between neutrinos and nucleons. This paper develops a charged-current quasielastic (CCQE) neutrino-nucleus scattering model to explore the nuclear mean-field dynamics and short-range correlation effects. In this model, the nuclear structure effect is depicted using the scaling function
\begin{document}$ f(\psi) $\end{document}
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, while the neutrino-nucleon interaction is represented by the elementary weak cross section
\begin{document}$ \sigma_0 $\end{document}
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. Results indicate that the double-differential cross section of scattered muon is influenced by the energy
\begin{document}$ E $\end{document}
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and momentum
\begin{document}$ {\bf{p}} $\end{document}
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of nucleon in nuclei, and the total cross section depends primarily on the incident neutrino energy
\begin{document}$ E_\nu $\end{document}
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. Furthermore, incorporating short-range correlations yields the flux-integrated differential cross sections at high-
\begin{document}$ T_\mu $\end{document}
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region producing larger values, a longer tail, and achieving better experimental consistency. It eventually elucidates the physical relationship between the neutrino-nucleus scattering cross section and the variation in incident neutrino energy. The studies in this paper furnish insights for the research of nucleon dynamics and provides detailed examinations of the neutrino-nucleus scattering mechanism.
In recent years, many studies on neutrino-nucleus scattering have been carried out to investigate nuclear structures and the interactions between neutrinos and nucleons. This paper develops a charged-current quasielastic (CCQE) neutrino-nucleus scattering model to explore the nuclear mean-field dynamics and short-range correlation effects. In this model, the nuclear structure effect is depicted using the scaling function
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We present the solution of a non-linear magnetic-charged black hole with an anisotropic matter field and further extend it to obtain the corresponding rotating black hole solution using the modified Newman-Janis algorithm. The event horizon and ergosphere of the rotating black hole are studied in terms of the perspective of geometric properties, revealing that the rotating black hole can have up to three horizons. The first law of thermodynamics and the squared-mass formula for the rotating black hole are derived from a thermodynamic perspective, based on which we obtain the thermodynamic quantities and study the thermodynamic stability of the rotating black hole. Additionally, we calculate the Penrose process for the rotating black hole, indicating the influence of various black hole parameters on the maximal efficiency of the Penrose process.
We present the solution of a non-linear magnetic-charged black hole with an anisotropic matter field and further extend it to obtain the corresponding rotating black hole solution using the modified Newman-Janis algorithm. The event horizon and ergosphere of the rotating black hole are studied in terms of the perspective of geometric properties, revealing that the rotating black hole can have up to three horizons. The first law of thermodynamics and the squared-mass formula for the rotating black hole are derived from a thermodynamic perspective, based on which we obtain the thermodynamic quantities and study the thermodynamic stability of the rotating black hole. Additionally, we calculate the Penrose process for the rotating black hole, indicating the influence of various black hole parameters on the maximal efficiency of the Penrose process.
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The effect of electron-electron interaction on positron emission in supercritical collisions of highly charged ions is studied within the monopole approximation using the time-dependent density functional theory and the time-dependent Hartree–Fock–Slater methods. Positron production probabilities and energy spectra are calculated for U–U, U–Cm, and Cm–Cm collision systems, considering both bare nuclei and highly charged ions with partially filled electron shells. The results demonstrate that screening of the nuclear potential by electrons along with Pauli blocking substantially reduce positron production and suppress the characteristic signatures of spontaneous vacuum decay, previously found in collisions of bare nuclei.
The effect of electron-electron interaction on positron emission in supercritical collisions of highly charged ions is studied within the monopole approximation using the time-dependent density functional theory and the time-dependent Hartree–Fock–Slater methods. Positron production probabilities and energy spectra are calculated for U–U, U–Cm, and Cm–Cm collision systems, considering both bare nuclei and highly charged ions with partially filled electron shells. The results demonstrate that screening of the nuclear potential by electrons along with Pauli blocking substantially reduce positron production and suppress the characteristic signatures of spontaneous vacuum decay, previously found in collisions of bare nuclei.
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Lepton flavor violation (LFV) offers a powerful probe of physics beyond the Standard Model, particularly in models addressing neutrino masses and the baryon asymmetry of the universe. In this study, we investigate LFV processes within the framework of type II seesaw leptogenesis, where the Standard Model is extended by an
\begin{document}$SU(2)_L$\end{document}
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triplet Higgs field. We focus on key LFV processes including
\begin{document}$\mu^+\to e^+\gamma$\end{document}
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,
\begin{document}$\mu^+ \to e^+e^-e^+$\end{document}
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, and
\begin{document}$\mu \rightarrow e$\end{document}
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conversion in nuclei, deriving stringent constraints on the parameter space from current experimental data. We scan the 3σrange of neutrino oscillation parameters and identify the most conservative bounds consistent with existing measurements. Our results reveal that the MEG experiment currently provides the strongest constraints in the normal ordering (NO) scenario, while the SINDRUM experiment offers comparable sensitivity in the inverted ordering (IO) case. Future experiments, such as MEG II, Mu3e, Mu2e, and COMET, are predicted to significantly improve the sensitivity, testing larger regions of the parameter space.
Lepton flavor violation (LFV) offers a powerful probe of physics beyond the Standard Model, particularly in models addressing neutrino masses and the baryon asymmetry of the universe. In this study, we investigate LFV processes within the framework of type II seesaw leptogenesis, where the Standard Model is extended by an
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We investigate the shadows and optical appearances of a new type of regular black holes (BHs) with a Minkowski core under different spherical accretion. These BHs are constructed by modifying the Newtonian potential based on the minimum observable length in the Generalized Uncertainty Principle (GUP). They correspond one-to-one with the traditional regular BHs with a de-Sitter (dS) core (such as Bardeen/Hayward BHs), characterized by quantum gravity effect parameter (
\begin{document}$ \alpha_0 $\end{document}
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) and spacetime deformation factor (n). We find that the characteristic parameters give rise to some novel observable features. For these new BHs, the shadow radius and the photon sphere radius decrease with the increase of
\begin{document}$ \alpha_0 $\end{document}
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, while the observed specific intensity increases. Conversely, asnincreases, the shadow radius and the photon sphere radius increase, whereas the observed specific intensity decreases. Under different spherical accretion, the shadows and the photon sphere radius are identical, but the observed specific intensity under the static spherical accretion is greater than that under the infalling spherical accretion. In addition, we find that these regular BHs with different cores show differences in shadows and optical appearances, especially under the static spherical accretion. Compared with Bardeen BH, the new BH has a smaller observed specific intensity, dimmer photon ring, and smaller shadow radius and photon sphere radius. The larger
\begin{document}$ \alpha_0 $\end{document}
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leads to more significant differences, and a similar trend is also seen in the comparison with Hayward BH. Under the infalling spherical accretion, these regular BHs with different cores only have slight differences in observed specific intensity, which become more obvious when
\begin{document}$ \alpha_0 $\end{document}
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is relatively large. It suggests that the unique spacetime features of these regular BHs with different cores can be distinguished through astronomical observations.
We investigate the shadows and optical appearances of a new type of regular black holes (BHs) with a Minkowski core under different spherical accretion. These BHs are constructed by modifying the Newtonian potential based on the minimum observable length in the Generalized Uncertainty Principle (GUP). They correspond one-to-one with the traditional regular BHs with a de-Sitter (dS) core (such as Bardeen/Hayward BHs), characterized by quantum gravity effect parameter (
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We investigate the influence of an early matter-dominated era in cosmic history on the dynamics of cosmic strings and the resulting stochastic gravitational waves. Specifically, we examine the case where this era originates from the dark matter dilution mechanism within the framework of the minimal left-right symmetric model. By numerically solving the Boltzmann equations governing the energy densities of the relevant components, we meticulously analyze the modifications to the cosmological scale factor, the number density of cosmic string loops, and the gravitational wave spectrum. Our results reveal that the early matter-dominated era causes a characteristic suppression in the high-frequency regime of the gravitational wave spectrum, providing distinct and testable signatures for future ground-based interferometer experiments.
We investigate the influence of an early matter-dominated era in cosmic history on the dynamics of cosmic strings and the resulting stochastic gravitational waves. Specifically, we examine the case where this era originates from the dark matter dilution mechanism within the framework of the minimal left-right symmetric model. By numerically solving the Boltzmann equations governing the energy densities of the relevant components, we meticulously analyze the modifications to the cosmological scale factor, the number density of cosmic string loops, and the gravitational wave spectrum. Our results reveal that the early matter-dominated era causes a characteristic suppression in the high-frequency regime of the gravitational wave spectrum, providing distinct and testable signatures for future ground-based interferometer experiments.
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Recent years have seen the development and growth of machine learning in high energy physics. There will be more effort to continue exploring its full potential. To make it easier for researchers to apply existing algorithms and neural networks and to advance the reproducibility of the analysis, we develop the HEP ML LAB (
\begin{document}$ \mathrm{hml}$\end{document}
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), a Python-based, end-to-end framework for phenomenology studies. It covers the complete workflow from event generation to performance evaluation, and provides a consistent style of use for different approaches. We propose an observable naming convention to streamline the data extraction and conversion processes. In the KERAS style, we provide the traditional cut-and-count and boosted decision trees together with neural networks. We take the $W^+$ tagging as an example and evaluate all built-in approaches with the metrics of significance and background rejection. With its modular design, HEP ML LAB is easy to extend and customize, and can be used as a tool for both beginners and experienced researchers.
Recent years have seen the development and growth of machine learning in high energy physics. There will be more effort to continue exploring its full potential. To make it easier for researchers to apply existing algorithms and neural networks and to advance the reproducibility of the analysis, we develop the HEP ML LAB (
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We consider two-loop planar contributions to a three-body form factor at the next-to-leading power in the high-energy limit, where the masses of external particles are much smaller than their energies. The calculation is performed by exploiting the differential equations of the expansion coefficients, both for facilitating the linear relations among them, and for deriving their analytic expressions. The result is written in terms of generalized polylogarithms involving a few simple symbol letters. Our method can be readily applied to the calculation of non-planar contributions as well. The result provides crucial information for establishing sub-leading factorization theorems for massive scattering amplitudes in the high-energy limit.
We consider two-loop planar contributions to a three-body form factor at the next-to-leading power in the high-energy limit, where the masses of external particles are much smaller than their energies. The calculation is performed by exploiting the differential equations of the expansion coefficients, both for facilitating the linear relations among them, and for deriving their analytic expressions. The result is written in terms of generalized polylogarithms involving a few simple symbol letters. Our method can be readily applied to the calculation of non-planar contributions as well. The result provides crucial information for establishing sub-leading factorization theorems for massive scattering amplitudes in the high-energy limit.
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Abstract:
Theα-decay half-lives of superheavy nuclei (SHN) with charge numberZ≥104 are investigated by employing a phenomenological one-parameter model based on the quantum-mechanical tunneling through a potential barrier where both the centrifugal and overlapping effects have been taken into account. It is shown that the experimentalα-decay half-lives of the 81 SHN are reproduced well. Moreover, the order of magnitude for theα-particle preformation probability inside a parent nucleus (
\begin{document}$S _{\alpha } $\end{document}
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) is found as
\begin{document}$ 10^{-2} $\end{document}
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. Then, within this model, the
\begin{document}$S _{\alpha } $\end{document}
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values andα-decay half-lives ofZ= 118-120 isotopes are predicted by inputting theα-decay energies (
\begin{document}$ Q_{\alpha } $\end{document}
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) extracted from the relativistic continuum Hartree-Bogoliubov (RCHB) theory, Duflo-Zuker 19 (DZ19, here 19 denotes the numbers of the fitting parameters.) model, improved Weizsacker-Skyrme (IMWS) model and machine learning (ML) approach, respectively. By analyzing the evolutions of
\begin{document}$ Q_{\alpha } $\end{document}
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,
\begin{document}$S _{\alpha } $\end{document}
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andα-decay half-lives ofZ= 118-120 isotopes with the neutron numberNof the parent nucleus, it is found that the shell effect atN= 184 are evident for all the nuclear mass models. Meanwhile, for the case of the RCHB,N= 172 is determined as a submagic number. However, the submagic number atN= 172 is replaced byN= 178 for the ML approach.
Theα-decay half-lives of superheavy nuclei (SHN) with charge numberZ≥104 are investigated by employing a phenomenological one-parameter model based on the quantum-mechanical tunneling through a potential barrier where both the centrifugal and overlapping effects have been taken into account. It is shown that the experimentalα-decay half-lives of the 81 SHN are reproduced well. Moreover, the order of magnitude for theα-particle preformation probability inside a parent nucleus (
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A horizonless ultracompact object can have a stable antiphoton sphere, which causes the strong deflection of photons inside the unstable photon sphere, leading to the formation of distinctive inner photon rings. In this work, we present analytical descriptions for the shape, thickness and interference pattern of higher-order inner photon rings. By taking the static spherically symmetric Schwarzschild star with a photon sphere as an example, we find that its inner photon rings can be more non-circular and thicker than the outer ones, and show that the inclusion of the inner photon rings can give rise to new features in the interferometric pattern. Our formulae can also be applied to other ultracompact objects, providing a convenient way to study the observational properties of their higher-order photon rings.
A horizonless ultracompact object can have a stable antiphoton sphere, which causes the strong deflection of photons inside the unstable photon sphere, leading to the formation of distinctive inner photon rings. In this work, we present analytical descriptions for the shape, thickness and interference pattern of higher-order inner photon rings. By taking the static spherically symmetric Schwarzschild star with a photon sphere as an example, we find that its inner photon rings can be more non-circular and thicker than the outer ones, and show that the inclusion of the inner photon rings can give rise to new features in the interferometric pattern. Our formulae can also be applied to other ultracompact objects, providing a convenient way to study the observational properties of their higher-order photon rings.
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The formalism for a quantitative treatment of high-momentum components of
\begin{document}$ NN $\end{document}
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momentum distributions for the spin-singlet channels is presented. The approach suggests the use of a distribution for a virtual state in momentum representation for the
\begin{document}$ NN $\end{document}
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channel in question as a universal one which can be further employed within contact formalisms for nuclei. It is shown how such distributions can be calculated from low-energy scattering wave functions in the same channels. As a result, a new characteristic (a constant) for the high-momentum part of the momentum distribution in a spin-singlet channel is introduced. As a test of the approach, we calculate the
\begin{document}$ pp $\end{document}
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nuclear contacts for
\begin{document}$ ^3 {\rm{He}}$\end{document}
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nucleus which occur to be nearly the same for four realistic
\begin{document}$ NN $\end{document}
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interactions with essentially different high-momentum properties. Found results should be useful for researchers studying the problem of short-range correlations in nuclei. In particular, the approach gives a generalization for the formalisms based on nuclear contacts.
The formalism for a quantitative treatment of high-momentum components of
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This study investigates a black hole surrounded by a cloud of strings and a cosmological dark fluid characterized by a modified Chaplygin-like equation of state (MCDF),
\begin{document}$ p=A\rho-B/\rho^{\beta} $\end{document}
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. We analyze its geodesic structure, shadow, and optical appearance. Analysis of the effective potential and epicyclic frequencies reveals that the existence of innermost/outermost stable circular orbits (ISCOs/OSCOs) for timelike particles is controlled by the parameters of the MCDF and the cloud of strings. The behavior of orbital conserved quantities and the Keplerian frequency are also examined. By equating the influence of the MCDF on the spacetime metric at spatial infinity with that of a cosmological constant, we constrain the MCDF parameters using the observed shadow radii of Sgr A* and M87*. We investigate the effects of the cloud of strings and MCDF on the black hole's shadows and optical images, assuming various thin disk accretion profiles. Using the method developed by Wald and collaborators, light trajectories are classified by their impact parameters into direct emission, the lensing ring, and the photon ring. The presence of OSCOs can lead to the existence of outer edges in the direct emission and lensing ring images. Observed brightness primarily originates from direct emission, with a minor contribution from the lensing ring, while the photon ring's contribution is negligible due to extreme demagnification. The influence of the cloud of strings and MCDF parameters on all results is analyzed throughout the study.
This study investigates a black hole surrounded by a cloud of strings and a cosmological dark fluid characterized by a modified Chaplygin-like equation of state (MCDF),
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Physics-Informed Neural Networks (PINNs) have emerged as a powerful tool for solving high-dimensional partial differential equations, demonstrating promising results across various fields of physics and engineering. In this study, We present the first application of PINNs to quantum tunneling in heavy-ion fusion reactions. By incorporating the physical laws directly into the neural network's loss function, PINNs enable the accurate solution of the multidimensional Schrödinger equation, whose wavefunction has substantial oscillations. The calculated quantum tunneling probabilities exhibit well agreement with those obtained using the finite element method at the considered near barrier energy region. Furthermore, we demonstrate a significant advantage of the PINN approach to save and fine-tune pre-trained neural networks for related tunneling calculations, thereby enhancing computational efficiency and adaptability.
Physics-Informed Neural Networks (PINNs) have emerged as a powerful tool for solving high-dimensional partial differential equations, demonstrating promising results across various fields of physics and engineering. In this study, We present the first application of PINNs to quantum tunneling in heavy-ion fusion reactions. By incorporating the physical laws directly into the neural network's loss function, PINNs enable the accurate solution of the multidimensional Schrödinger equation, whose wavefunction has substantial oscillations. The calculated quantum tunneling probabilities exhibit well agreement with those obtained using the finite element method at the considered near barrier energy region. Furthermore, we demonstrate a significant advantage of the PINN approach to save and fine-tune pre-trained neural networks for related tunneling calculations, thereby enhancing computational efficiency and adaptability.
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We constrain the symmetry energy slopeLat the saturation density using the neutron skin values of48Ca,64Ni,124Sn, and208Pb determined by various experiments. The resultingLof 50(6) MeV is consistent with the world-averaged value from different observables and methodologies. Furthermore, the implications of newly constrainedLon the radius determinations of 1.4 solar-mass neutron stars are also discussed based on the established
\begin{document}$ R_{1.4}$\end{document}
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-Llinear relationships by the DD-ME2 and TW99 EoS families.
We constrain the symmetry energy slopeLat the saturation density using the neutron skin values of48Ca,64Ni,124Sn, and208Pb determined by various experiments. The resultingLof 50(6) MeV is consistent with the world-averaged value from different observables and methodologies. Furthermore, the implications of newly constrainedLon the radius determinations of 1.4 solar-mass neutron stars are also discussed based on the established
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Based on the extended projected shell model – a microscopic nuclear many-body theory – we have revealed an unexpected phenomenon (
\begin{document}$ \Delta I = 2 $\end{document}
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bifurcation) in rotational bands associated with scissors vibrations in
\begin{document}$ ^{156} {\rm{Gd}}$\end{document}
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in our recently published article [Phys. Rev. Lett. 129, 042502 (2022)]. In the present work, we extended the study by systematically changing the model parameters (deformation and strength of the monopole-pairing force) for the
\begin{document}$ ^{156} {\rm{Gd}}$\end{document}
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calculation. We also calculated additional isotopes and isotones with respect to
\begin{document}$ ^{156} {\rm{Gd}}$\end{document}
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. In all calculations, we found a similar occurrence of the
\begin{document}$ \Delta I = 2 $\end{document}
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bifurcation in the results. We thus confirmed that the bifurcation behavior of the scissors' rotation bands originates from the self-organizing effects of deformed proton and neutron bodies during the scissors motion, independently of the model parameters.
Based on the extended projected shell model – a microscopic nuclear many-body theory – we have revealed an unexpected phenomenon (
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This study explores the thermodynamics, quantum tunneling phenomena, and unique orbital properties of Einstein-Power-Yang-Mills (EPYM) black holes embedded in Anti-de Sitter (AdS) spacetimes, highlighting the role of the nonlinear Yang-Mills (YM) charge parameterγ. We derive explicit expressions for the black hole metric, horizon structure, and associated thermodynamic quantities, including Hawking temperature and phase transitions. Using the WKB approximation and Hamilton-Jacobi formalism, we investigate the quantum tunneling of massive
\begin{document}$ W^+ $\end{document}
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bosons, revealing how nonlinear YM interactions significantly alter the radiation spectrum and emission rates. We analyze the effective potential for scalar field propagation, showing that nonlinear YM effects produce distinctive modifications in potential barriers and radiation emission processes. Additionally, our study uncovers the presence of the Aschenbach effect, typically exclusive to rotating black holes, in static and spherically symmetric EPYM black hole solutions.
This study explores the thermodynamics, quantum tunneling phenomena, and unique orbital properties of Einstein-Power-Yang-Mills (EPYM) black holes embedded in Anti-de Sitter (AdS) spacetimes, highlighting the role of the nonlinear Yang-Mills (YM) charge parameterγ. We derive explicit expressions for the black hole metric, horizon structure, and associated thermodynamic quantities, including Hawking temperature and phase transitions. Using the WKB approximation and Hamilton-Jacobi formalism, we investigate the quantum tunneling of massive
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The production, dynamic evolution, and decay of
\begin{document}$ \Delta $\end{document}
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particles play a crucial role in understanding the properties of high baryon density nuclear matter in intermediate-energy heavy-ion collisions. In this work, the energy-, density-, and isospin-dependent nucleon-
\begin{document}$ \Delta $\end{document}
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elastic cross section (
\begin{document}$ \sigma^{*}_{N \Delta} $\end{document}
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) is studied within the framework of the relativistic Boltzmann-Uehling-Uhlenbeck transport theory, in which the
\begin{document}$ \delta $\end{document}
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meson field is further considered beside the
\begin{document}$ \sigma $\end{document}
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,
\begin{document}$ \omega $\end{document}
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, and
\begin{document}$ \rho $\end{document}
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meson fields. The results show that the
\begin{document}$ \delta $\end{document}
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and
\begin{document}$ \rho $\end{document}
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meson related exchange terms have a nonnegligible contribution to the
\begin{document}$ \sigma^{*}_{N \Delta} $\end{document}
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compared to only considering the
\begin{document}$ \rho $\end{document}
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meson exchange terms, although there is a significant cancellation on the cross section among these meson exchange terms. In addition, due to the different effects of the medium correction on the effective mass of neutrons, protons, and differently charged
\begin{document}$ \Delta $\end{document}
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s, the individual
\begin{document}$ \sigma^{*}_{N \Delta} $\end{document}
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exhibits an ordered isospin-asymmetry (
\begin{document}$ \alpha $\end{document}
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) dependence, and
\begin{document}$ \sigma^{*}_{n\Delta} $\end{document}
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and
\begin{document}$ \sigma^{*}_{p\Delta} $\end{document}
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have opposite
\begin{document}$ \alpha $\end{document}
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dependencies. And the
\begin{document}$ \alpha $\end{document}
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dependence of the ratio
\begin{document}$ R(\alpha)=\sigma^{*}(\alpha)/\sigma^{*}(\alpha=0) $\end{document}
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for
\begin{document}$ n\Delta $\end{document}
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reaction channels follow
\begin{document}$ n\Delta^{++}>n\Delta^{+}>n\Delta^{0}>n\Delta^{-} $\end{document}
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, while for
\begin{document}$ p\Delta $\end{document}
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it is
\begin{document}$ p\Delta^{-}>p\Delta^{0}>p\Delta^{+}>p\Delta^{++} $\end{document}
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. Moreover, the results also indicate that the isospin effect on the
\begin{document}$ \sigma^{*}_{N \Delta} $\end{document}
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, which is dominantly caused by the isovector
\begin{document}$ \rho $\end{document}
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and
\begin{document}$ \delta $\end{document}
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meson fields, is still pronounced at densities up to 3 times normal nuclear density. Finally, a parametrization of the energy-, density-, and isospin-dependent
\begin{document}$ N\Delta $\end{document}
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elastic cross section is proposed based on the microscopic calculated results, and the in-medium
\begin{document}$ \sigma^{*}_{N \Delta} $\end{document}
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in the energy range of
\begin{document}$ \sqrt{s} $\end{document}
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=2.3~3.0 GeV can be well described.
The production, dynamic evolution, and decay of
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In this work, we extend our previous work on the
\begin{document}$ D^*\bar{D}^* $\end{document}
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molecular states with the
\begin{document}$ J^{PC}=0^{++} $\end{document}
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,
\begin{document}$ 1^{+-} $\end{document}
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and
\begin{document}$ 2^{++} $\end{document}
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to investigate their two-body strong decays via the QCD sum rules based on rigorous quark-hadron duality. We obtain the partial decay widths therefore total widths of the ground states with the
\begin{document}$ J^{PC}=0^{++} $\end{document}
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,
\begin{document}$ 1^{+-} $\end{document}
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and
\begin{document}$ 2^{++} $\end{document}
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, which indicate that it is reasonable to assign the
\begin{document}$ X_2(4014) $\end{document}
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as the
\begin{document}$ D^*\bar{D}^* $\end{document}
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tetraquark molecular states with the
\begin{document}$ J^{PC}=2^{++} $\end{document}
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.
In this work, we extend our previous work on the
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Nuclear reaction studies on unstable isotopes can strongly help in improving our understanding of nucleosynthesis in stars. Indirect approaches to determining astrophysical reaction rates are increasingly common-place and undergoing continuous refinement. Of particular interest is the use of such indirect techniques at storage rings, which, among other allow to recycle rare unstable beams. We propose to investigate reaction rates of astrophysical interest using indirect methods (surrogate, Trojan horse….) in reverse kinematics at the IMP-CAS storage ring. Long lived radioactive ion beams, produced remotely, can be accelerated, and made interacting with light targets. Proposed reactions are85Kr(p,p’γ),85Kr(d,pγ),constraining the neutron flux in an s-process branching point,79Se(p,p’γ),79Se(d,pγ),constraining the temperature in s-process nucleosyntheses,59Fe(d,pγ), constraining core collapse supernovae.
Nuclear reaction studies on unstable isotopes can strongly help in improving our understanding of nucleosynthesis in stars. Indirect approaches to determining astrophysical reaction rates are increasingly common-place and undergoing continuous refinement. Of particular interest is the use of such indirect techniques at storage rings, which, among other allow to recycle rare unstable beams. We propose to investigate reaction rates of astrophysical interest using indirect methods (surrogate, Trojan horse….) in reverse kinematics at the IMP-CAS storage ring. Long lived radioactive ion beams, produced remotely, can be accelerated, and made interacting with light targets. Proposed reactions are85Kr(p,p’γ),85Kr(d,pγ),constraining the neutron flux in an s-process branching point,79Se(p,p’γ),79Se(d,pγ),constraining the temperature in s-process nucleosyntheses,59Fe(d,pγ), constraining core collapse supernovae.
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Within the framework of the perturbative QCD approach utilizing
\begin{document}$k_T$\end{document}
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factorization, we have investigated the CP violation and branching ratios in the decay processes of
\begin{document}$B_{c}^{+}\to D_{(s)} ^{+}V(V\rightarrow\pi^{+}\pi^{-})$\end{document}
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and
\begin{document}$B_{c}^{+}\to D_{(s)}^{+}V(V\rightarrow K^{+}K^{-})$\end{document}
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, where V denotes the three vector mesons
\begin{document}$\rho^0$\end{document}
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,ω, andϕ. During the
\begin{document}$V\to \pi^+\pi^-$\end{document}
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and
\begin{document}$V\to K^+K^-$\end{document}
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decay processes, we incorporated the
\begin{document}$\rho^{0}-\omega-\phi$\end{document}
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mixing mechanism to describe the amplitudes of these quasi-two-body decays. Within the interference region of the three vector particles, we observed distinct changes in both CP violations and branching ratios. Furthermore, our study presents evidence for local CP violations and branching ratios that warrants further investigation through experiments.
Within the framework of the perturbative QCD approach utilizing
Published:
Abstract:
Recent parameterizations of parton distribution functions (PDFs) have led to the determination of the gravitional form factors of the nucleon's dependence on generalized parton distributions of nucleons in the limit
\begin{document}$\xi \to 0 $\end{document}
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. This paper aims to obtain the flavor division of nucleon electromagnetic and gravitional form factors using the VS24 Ansatz and two PDFs at
\begin{document}$ N^3L0 $\end{document}
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approximation in GPDs. The PDFs and GPDs formalism enable the calculation of various form factors of nucleons in different approximations, as well as the calculation of the electric radius of nucleons. The study, despite its high approximation complexity, enhances the accuracy of calculations and brings them closer to the experimental values.
Recent parameterizations of parton distribution functions (PDFs) have led to the determination of the gravitional form factors of the nucleon's dependence on generalized parton distributions of nucleons in the limit
Published:
, doi:10.1088/1674-1137/add25e
Abstract:
In this study, we investigate the impact of rotation on the thermodynamic characteristics of QCD matter using the three-flavor NJL model. We examine the temperature, quark chemical potential, and angular velocity dependencies of key thermodynamic quantities, such as the trace anomaly, specific heat, speed of sound, angular momentum, and moment of inertia. As the main finding of our analysis, we observe that the speed of sound exhibits a nonmonotonic behavior as the angular velocity changes.
In this study, we investigate the impact of rotation on the thermodynamic characteristics of QCD matter using the three-flavor NJL model. We examine the temperature, quark chemical potential, and angular velocity dependencies of key thermodynamic quantities, such as the trace anomaly, specific heat, speed of sound, angular momentum, and moment of inertia. As the main finding of our analysis, we observe that the speed of sound exhibits a nonmonotonic behavior as the angular velocity changes.
Published:
Abstract:
Fox-Wolfram Moments (FWMs) are a set of event shape observables that characterize the angular distribution of energy flow in high-energy collisions. In this work, we present the first theoretical investigation of FWMs for multi-jet production in relativistic heavy ion collisions. In this work, jet productions in p+p collisions are computed with a Monte Carlo event generator SHERPA, while the Linear Boltzmann Transport model is utilized to simulate the multiple scattering of energetic partons in the hot and dense QCD matter. The event-normalized distributions of the lower-order FWM,
\begin{document}$H_1^T$\end{document}
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in p+p and Pb+Pb collisions are calculated. It is found that for events with jet number
\begin{document}$n_\text{jet} = 2$\end{document}
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the
\begin{document}$H_1^T$\end{document}
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distribution in Pb+Pb is suppressed at small
\begin{document}$H_1^T$\end{document}
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while enhanced at large
\begin{document}$H_1^T$\end{document}
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region as compared to p+p. For events with
\begin{document}$n_\text{jet}>2$\end{document}
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, the jet number reduction effect due to jet quenching in the QGP decreases the
\begin{document}$H_1^T$\end{document}
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distribution at large
\begin{document}$H_1^T$\end{document}
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in Pb+Pb relative to p+p. The medium modification of the Fox-Wolfram moment
\begin{document}$H_1^T$\end{document}
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for events with
\begin{document}$n_\text{jet}\ge 2$\end{document}
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are also presented, which resemble those of events with
\begin{document}$n_\text{jet} = 2$\end{document}
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. Its reason is revealed through the relative contribution fractions of events with different final-state jet numbers to
\begin{document}$H_1^T$\end{document}
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.
Fox-Wolfram Moments (FWMs) are a set of event shape observables that characterize the angular distribution of energy flow in high-energy collisions. In this work, we present the first theoretical investigation of FWMs for multi-jet production in relativistic heavy ion collisions. In this work, jet productions in p+p collisions are computed with a Monte Carlo event generator SHERPA, while the Linear Boltzmann Transport model is utilized to simulate the multiple scattering of energetic partons in the hot and dense QCD matter. The event-normalized distributions of the lower-order FWM,
Published:
Abstract:
Highly linear correlation between the charge radii difference of mirror-pair nuclei and the slope parameter of symmetry energy has been built in the existing literatures. In this work, the impact of neutron-proton correlation deduced from the neutron- and proton-pairs condensation around the Fermi surface on determining the slope parameter of nuclear symmetry energy is investigated based on the Skyrme density functionals. The differential charge radii of Ni isotopes are employed to inspect the validity of this recently developed model. The calculated results suggest that the modified model can reproduce the shell quenching of charge radii at the neutron number
\begin{document}$ N=28 $\end{document}
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along Ni isotopic chain. The shell closure effect of the charge radii can also be predicted at the neutron number
\begin{document}$ N=50 $\end{document}
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. The correlations between the charge radii differences of mirror partner nuclei32Ar-32Si and54Ni-54Fe and the slope parameters of symmetry energy are also analyzed. It is shown that the covered range of the symmetry energy slope is influenced by the neutron-pairs condensation around the Fermi surface. Moreover, a relatively stiff equation of state can be inferred from the mirror pairs32Ar-32Si and54Ni-54Fe when the influence coming from the neutron-pairs condensation is taken into account.
Highly linear correlation between the charge radii difference of mirror-pair nuclei and the slope parameter of symmetry energy has been built in the existing literatures. In this work, the impact of neutron-proton correlation deduced from the neutron- and proton-pairs condensation around the Fermi surface on determining the slope parameter of nuclear symmetry energy is investigated based on the Skyrme density functionals. The differential charge radii of Ni isotopes are employed to inspect the validity of this recently developed model. The calculated results suggest that the modified model can reproduce the shell quenching of charge radii at the neutron number
The lepton-number-violating pion decay and the type-I seesaw mechanism in chiral perturbation theory
Published:
Abstract:
We investigate the process of lepton-number-violating pion decay, which dominates the nuclear neutrinoless double beta decay induced by the short-range operator, within the type-I seesaw mechanism. The type-I seesaw mechanism gives rise to the Dirac and Majorana mass terms of neutrinos by introducing the gauge-singlet right-handed neutrinos, which are usually called sterile neutrinos. Using chiral perturbation theory, the transition amplitudes in the case of the light and heavy sterile neutrinos are calculated up to
\begin{document}$ \mathcal{O}(Q^2/\Lambda^2_\chi) $\end{document}
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respectively, whereQis the typical low-energy scale in this process and
\begin{document}$ \Lambda_\chi $\end{document}
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the chiral symmetry breaking scale. We then adopt a naive interpolation formula of mass dependence to obtain the amplitude in the full mass range and briefly discuss its validity.
We investigate the process of lepton-number-violating pion decay, which dominates the nuclear neutrinoless double beta decay induced by the short-range operator, within the type-I seesaw mechanism. The type-I seesaw mechanism gives rise to the Dirac and Majorana mass terms of neutrinos by introducing the gauge-singlet right-handed neutrinos, which are usually called sterile neutrinos. Using chiral perturbation theory, the transition amplitudes in the case of the light and heavy sterile neutrinos are calculated up to
Published:
Abstract:
Shell evolution is crucial for understanding nuclear structures across the nuclear chart. In this work, we employed theab initiovalence space in-medium similarity renormalization group with chiral nucleon-nucleon and three-nucleon interactions to study neutron-rich Si, S, Ar, and Ca isotopes, particularly focusing on nuclei near
\begin{document}$ N=32, 34 $\end{document}
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. We systematically analyzed both neutron and proton shell evolutions by examining the excitation energies of the first
\begin{document}$ 2^+ $\end{document}
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states and the effective single-particle energies. Our calculations show that the
\begin{document}$ N=32 $\end{document}
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sub-shell gradually weakens as protons are removed from the doubly magic nucleus
\begin{document}$ ^{52} {\rm{Ca}}$\end{document}
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, eventually disappearing in
\begin{document}$ ^{46} {\rm{Si}}$\end{document}
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. Conversely, the strength of the
\begin{document}$ N=34 $\end{document}
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sub-shell is enhanced with the removal of protons from
\begin{document}$ ^{54} {\rm{Ca}}$\end{document}
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. Furthermore, our results indicate the existence of the proton
\begin{document}$ Z=14 $\end{document}
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sub-shell in neutron-rich Si isotopes. These findings suggest that
\begin{document}$ ^{48} {\rm{Si}}$\end{document}
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is a doubly magic nucleus, with the excitation energy of the first
\begin{document}$ 2^+ $\end{document}
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state around 2.49 MeV, which is about 400 keV higher than that of
\begin{document}$ ^{54} {\rm{Ca}}$\end{document}
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. This value is comparable to that of other well-known exotic doubly magic nuclei, such as
\begin{document}$ ^{52} {\rm{Ca}}$\end{document}
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and
\begin{document}$ ^{78} {\rm{Ni}}$\end{document}
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, which is extremely interesting for further experiments in RIB facilities. In addition, we predicted the low-lying spectra of neutron-rich Si, S, and Ar isotopes, providing new insights for future experiments.
Shell evolution is crucial for understanding nuclear structures across the nuclear chart. In this work, we employed theab initiovalence space in-medium similarity renormalization group with chiral nucleon-nucleon and three-nucleon interactions to study neutron-rich Si, S, Ar, and Ca isotopes, particularly focusing on nuclei near
Published:
Abstract:
In this paper, we study the production of doubly charmed baryon from anti-bottom charmed meson. Using the effective Lagrangian approach, we discuss triangle diagrams in hadronic level to get access to the branching ratios of
\begin{document}$\overline{B}_c\to {\cal{B}}_{ccq}+{\cal{B}}_{\bar c\bar q\bar q}$\end{document}
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. It seems that the specific process
\begin{document}$\overline {B}_c \to \Xi_{cc}^{+} \, \overline {\Xi}_{\bar c}^{'0}$\end{document}
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occupies the largest possibility in the order of
\begin{document}$9.1\times 10^{-5}$\end{document}
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. In addition, although the production of undiscovered
\begin{document}$\Omega_{cc}^+$\end{document}
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is Cabibbo suppressed in
\begin{document}$\overline B_c\to \Omega_{cc}^+ \, \overline {\Xi}_{\bar c}^0$\end{document}
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, it's branching ratio can still reach
\begin{document}$10^{-7}$\end{document}
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level. These results are excepted to be fairly valuable supports for future experiments.
In this paper, we study the production of doubly charmed baryon from anti-bottom charmed meson. Using the effective Lagrangian approach, we discuss triangle diagrams in hadronic level to get access to the branching ratios of
Published:
Abstract:
We study the
\begin{document}$ \cos2\phi $\end{document}
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azimuthal asymmetry in doubly longitudinally polarized proton-proton Drell-Yan collisions within the transverse momentum dependent factorization framework. The asymmetry arises from the convolution of the longitudinal transversity distribution
\begin{document}$ h_{1L}^{\perp} $\end{document}
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for both protons. Using the Bacchetta-Delcarro-Pisano-Radici-Signori parametrization for the nonperturbative Sudakov form factor and the Wandzura-Wilczek approximation for the collinear
\begin{document}$ h_{1L}^{\perp} $\end{document}
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, we predict the double spin asymmetry
\begin{document}$ A_{LL}^{\cos2\phi} $\end{document}
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at RHIC and NICA kinematics. Our results demonstrate sensitivity to sea quark distributions, with the asymmetry reaching up to 25% for maximal sea quark contributions. These predictions highlight the potential of polarized Drell-Yan measurements to probe sea quark dynamics and advance our understanding of nucleon structure.
We study the
Published:
Abstract:
A position-sensitive Schottky Cavity Doublet (SCD) has been developed to improve the accuracy of isochronous mass measurement at the Rare Radio-Isotope Ring (R3) at RIBF-RIKEN, Japan. The aim is to increase the accuracy of the position measurement which is used to correct the momentum spread, thus reducing the uncertainty in the mass determination. The detector consists of a cylindrical reference cavity and an elliptical position-sensitive cavity which uses an offset beam-pipe to make a relation between the Schottky power and the horizontal position. The uncertainty in the power response can be improved by minimising free parameters inside the power equation, providing a second-order correction for the position determination. This requires a large dispersion and momentum spread to effectively characterise the SCD acceptance, which simulations show is achieved when using76Zn as a reference isotope. A key parameter to minimise is the uncertainty of the impedance map which relates power to position in the elliptical cavity. We find that an uncertainty in impedance of 0.3 Ω results in a precision equal to that of the current mass measurement method. Additionally, measuring momentum with the SCD enables the removal of other detectors from the beam-line which drastically reduce the yield of high Z beams via charge-change interactions.
A position-sensitive Schottky Cavity Doublet (SCD) has been developed to improve the accuracy of isochronous mass measurement at the Rare Radio-Isotope Ring (R3) at RIBF-RIKEN, Japan. The aim is to increase the accuracy of the position measurement which is used to correct the momentum spread, thus reducing the uncertainty in the mass determination. The detector consists of a cylindrical reference cavity and an elliptical position-sensitive cavity which uses an offset beam-pipe to make a relation between the Schottky power and the horizontal position. The uncertainty in the power response can be improved by minimising free parameters inside the power equation, providing a second-order correction for the position determination. This requires a large dispersion and momentum spread to effectively characterise the SCD acceptance, which simulations show is achieved when using76Zn as a reference isotope. A key parameter to minimise is the uncertainty of the impedance map which relates power to position in the elliptical cavity. We find that an uncertainty in impedance of 0.3 Ω results in a precision equal to that of the current mass measurement method. Additionally, measuring momentum with the SCD enables the removal of other detectors from the beam-line which drastically reduce the yield of high Z beams via charge-change interactions.
Published:
Abstract:
We investigate the properties of the radially excited charged pion, with a specific focus on its electromagnetic form factor (EFF) and its box contribution to the hadronic light-by-light (HLbL) component of the muon's anomalous magnetic moment,
\begin{document}$ a_{\mu} $\end{document}
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. Utilizing a coupled non-perturbative framework combining Schwinger-Dyson and Bethe-Salpeter equations, we first compute the mass and weak decay constant of the pion's first radial excitation. Initial results are provided for the Rainbow-Ladder (RL) approximation, followed by an extended beyond RL (BRL) analysis that incorporates meson cloud effects. Building on our previous work, this analysis demonstrates that an accurate description of the first radial excitation can be achieved without the need for a reparametrization of the interaction kernels. Having demonstrated the effectiveness of the truncation scheme, we proceed to calculate the corresponding EFF, from which we derive the contribution of the pion's first radial excitation to the HLbL component of the muon's anomalous magnetic moment, producing
\begin{document}$ a_{\mu}^{\pi_1-\text{box}}(\text{RL}) = -(2.03 \pm 0.12) \times 10 ^{-13} $\end{document}
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,
\begin{document}$ a_{\mu}^{\pi_1-\text{box}}(\text{BRL}) = $\end{document}
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\begin{document}$ -(2.02 \pm 0.10) \times 10 ^{-13} $\end{document}
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. Our computation also sets the groundwork for calculating related pole contributions of excited pseudoscalar mesons to
\begin{document}$ a_{\mu} $\end{document}
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.
We investigate the properties of the radially excited charged pion, with a specific focus on its electromagnetic form factor (EFF) and its box contribution to the hadronic light-by-light (HLbL) component of the muon's anomalous magnetic moment,
Published:
Abstract:
In this paper, a feedforward neural network (FNN) approach is employed to optimize three local mass models (GK, GKs, and GK+J). It is found that adding physical quantities related to pairing effect in the input layer can effectively improve the prediction accuracy of local models. For the known masses in AME2012, the FNN reduces the root-mean-square deviation between theory and experiment for the three mass models by 11 keV, 32 keV and 623 keV. Among them, the improvement effect of light mass region with mass number between 16 and 60 is better than that of medium and heavy mass regions. It also has good optimization results when extrapolating AME2012 to AME2020 and the latest measured masses after AME2020. Based on the improved mass data, the separation energies for single- and two-proton (neutron) emissions, andα-decay energies are obtained, which agree well with the experiment.
In this paper, a feedforward neural network (FNN) approach is employed to optimize three local mass models (GK, GKs, and GK+J). It is found that adding physical quantities related to pairing effect in the input layer can effectively improve the prediction accuracy of local models. For the known masses in AME2012, the FNN reduces the root-mean-square deviation between theory and experiment for the three mass models by 11 keV, 32 keV and 623 keV. Among them, the improvement effect of light mass region with mass number between 16 and 60 is better than that of medium and heavy mass regions. It also has good optimization results when extrapolating AME2012 to AME2020 and the latest measured masses after AME2020. Based on the improved mass data, the separation energies for single- and two-proton (neutron) emissions, andα-decay energies are obtained, which agree well with the experiment.
Published:
Abstract:
Our previous study [A. H. Al-Ghamdi et al, JTUSCI 16 (2022) 1026] provided a comprehensive analysis of elastic scattering angular distributions (ADs) for the7Li +28Si system. This analysis aimed to identify the types of threshold anomaly, specifically normal or breakup, by examining the energy dependence of volume integrals across various interaction potentials. The current study extends this work by investigating the effects of7Li breakup into a valence particle (triton) orbiting a core (alpha) in the context of a28Si target, as well as the influence of the28Si(7Li,α)31P triton transfer reaction on the elastic ADs of the7Li +28Si system. The results demonstrate the significance of coupling to the7Li breakup channel and its subsequent impact on the elastic scattering channel. This strong coupling generates a dynamic polarization potential (DPP), leading to a reduction in potential strengths. A semi-microscopic DPP approach was utilized to model this effect, employing the continuum discretized coupled channels (CDCC) method. An effective potential (Ueff), considered as the sum of cluster folding and dynamic polarization potentials, the later was generated using the trivially equivalent local potential (TELP) approach, was employed successfully to reproduce the7Li +28Si ADs data. Furthermore, the analysis was broadened to assess the effect of the triton stripping reaction28Si(7Li,α)31P on the elastic7Li +28Si scattering.
Our previous study [A. H. Al-Ghamdi et al, JTUSCI 16 (2022) 1026] provided a comprehensive analysis of elastic scattering angular distributions (ADs) for the7Li +28Si system. This analysis aimed to identify the types of threshold anomaly, specifically normal or breakup, by examining the energy dependence of volume integrals across various interaction potentials. The current study extends this work by investigating the effects of7Li breakup into a valence particle (triton) orbiting a core (alpha) in the context of a28Si target, as well as the influence of the28Si(7Li,α)31P triton transfer reaction on the elastic ADs of the7Li +28Si system. The results demonstrate the significance of coupling to the7Li breakup channel and its subsequent impact on the elastic scattering channel. This strong coupling generates a dynamic polarization potential (DPP), leading to a reduction in potential strengths. A semi-microscopic DPP approach was utilized to model this effect, employing the continuum discretized coupled channels (CDCC) method. An effective potential (Ueff), considered as the sum of cluster folding and dynamic polarization potentials, the later was generated using the trivially equivalent local potential (TELP) approach, was employed successfully to reproduce the7Li +28Si ADs data. Furthermore, the analysis was broadened to assess the effect of the triton stripping reaction28Si(7Li,α)31P on the elastic7Li +28Si scattering.
Published:
Abstract:
We calculate the exact values of the quasinormal frequencies for massless perturbations with spin
\begin{document}$ s\leq2 $\end{document}
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moving in pure accelerating spacetime. We use two different methods to transfer the perturbation equations into the form of hypergeometric differential equations and obtain the same quasinormal frequencies. These purely imaginary spectra are shown to be independent of the spin of the perturbation and match those of the so-called acceleration modes of accelerating black holes after taking the Minkowski limit. This implies that the acceleration modes actually originate from the pure accelerating spacetime and the appearance of black holes would deform the spectra. In addition, we calculate the quasinormal frequencies of scalar, electromagnetic and gravitational perturbations ofD-dimensional de Sitter spacetime and compare them with previous results to verify the validity of our method.
We calculate the exact values of the quasinormal frequencies for massless perturbations with spin
Published:
Abstract:
The rare radioactive-isotope (RI) ring is an isochronous storage ring for deriving the masses of extremely short-lived rare RIs. Since the successful commissioning experiment in 2015, the time of flight mass measurement technique has been established through the test experiments using unstable nuclei with well-known masses. The experiments for unknown masses were started in 2018. While conducting the experiments, we continue to develop equipment to further improve the efficiency and precision for mass measurements. The upgraded kicker system can make a magnetic field with an extractable duration equivalent to revolution time of the ring. It is essential for extracting extremely rare events as well as shortening the measurement time compared with the initial experiments. New steering magnets make it possible to eliminate uncertain vertical beam deviation that occurres upstream. As a result, we confirmed that the extraction yield was increased. A new resonant Schottky pick-up is able to detect single particles in timeframes on the order of milliseconds. It will be useful not only for beam diagnostics, but also for lifetime measurement experiments of extremely short-lived rare RIs planned as a future application.
The rare radioactive-isotope (RI) ring is an isochronous storage ring for deriving the masses of extremely short-lived rare RIs. Since the successful commissioning experiment in 2015, the time of flight mass measurement technique has been established through the test experiments using unstable nuclei with well-known masses. The experiments for unknown masses were started in 2018. While conducting the experiments, we continue to develop equipment to further improve the efficiency and precision for mass measurements. The upgraded kicker system can make a magnetic field with an extractable duration equivalent to revolution time of the ring. It is essential for extracting extremely rare events as well as shortening the measurement time compared with the initial experiments. New steering magnets make it possible to eliminate uncertain vertical beam deviation that occurres upstream. As a result, we confirmed that the extraction yield was increased. A new resonant Schottky pick-up is able to detect single particles in timeframes on the order of milliseconds. It will be useful not only for beam diagnostics, but also for lifetime measurement experiments of extremely short-lived rare RIs planned as a future application.
Published:
Abstract:
We propose a search strategy at the HL-LHC for a new neutral particleXthat couples toW-bosons, using the process
\begin{document}$ p p \to W^{\pm} X (\to W^{+} W^{-}) $\end{document}
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with a tri-W-boson final state. Focusing on events with two same-sign leptonicW-boson decays into muons and a hadronically decayingW-boson, our method leverages the enhanced signal-to-background discrimination achieved through a machine-learning-based multivariate analysis. Using the heavy photophobic axion-like particle (ALP) as a benchmark, we evaluate the discovery sensitivities on both production cross section times branching ratio
\begin{document}$ \sigma(p p \to W^{\pm} X) \times \text{Br}(X \to W^{+} W^{-}) $\end{document}
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and the coupling
\begin{document}$ g_{aWW} $\end{document}
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for the particle mass over a wide range of 170–3000 GeV at the HL-LHC with center-of-mass energy
\begin{document}$ \sqrt{s} = 14 \, \text{ TeV} $\end{document}
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and integrated luminosity
\begin{document}$ {\cal{L}} = 3 \, \text{ab}^{-1} $\end{document}
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. Our results show significant improvements in discovery sensitivity, particularly for masses above 300 GeV, compared to existing limits derived from CMS analyses of Standard Model (SM) tri-W-boson production at
\begin{document}$ \sqrt{s} = 13 \, \text{ TeV} $\end{document}
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. This study demonstrates the potential of advanced selection techniques in probing the coupling of new particles toW-bosons and highlights the HL-LHC's capability to explore the physics beyond the SM.
We propose a search strategy at the HL-LHC for a new neutral particleXthat couples toW-bosons, using the process
Published:
, doi:10.1088/1674-1137/adcf10
Abstract:
We analyzed quasifission lifetimes of superheavy elements (SHEs) within
\begin{document}$ 104\le Z\le 120 $\end{document}
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and mass number range
\begin{document}$ 243\le A\le 301 $\end{document}
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considering various projectile-target combinations. Nucleus-nucleus potentials were evaluated using the nuclear proximity 2010 model, and quasifission barriers were evaluated as the difference between minimum and maximum potentials. The quasifission lifetimes varied from 0.1 zs to 2040 zs, with lifetimes above 1600 zs for
\begin{document}$ ^{249}_{145} $\end{document}
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Rf,
\begin{document}$ ^{248}_{143} $\end{document}
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Db,
\begin{document}$ ^{260}_{154} $\end{document}
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Sg, and
\begin{document}$ ^{263}_{156} $\end{document}
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Hs. The quasifission lifetimes decreased with increasing Z, dropping to 0.1 zs at Z=120. Shorter quasifission lifetimes may contribute to the reduction in production cross-sections from nanobarns to picobarns for elements with Z=104 to Z=118. Furthermore, the impact of angular momentum on quasifission barriers exhibits a decreasing trend as the atomic number increases. The shortest lifetime of 253 zs is observed at Z= 120 while longer lifetimes, such as 659 zs for64Ni+196Pt, suggest enhanced stability. The model was validated against data available in literature, generally producing lower values except for34S+186W, and238U+48Ca, where significant increases were observed.
We analyzed quasifission lifetimes of superheavy elements (SHEs) within
Published:
Abstract:
We investigate the entanglement harvesting protocol within the context of cylindrical gravitational waves given first by Einstein and Rosen, focusing on the interactions between non-relativistic quantum systems and linearized quantum gravity. We study how two spatially separated detectors can extract entanglement from the specific spacetime in the presence of gravitational waves, which provides a precise quantification of the entanglement that can be harvested using these detectors. In particular, we obtain the relation between harvested entanglement and the distance to wave sources that emits gravitational waves and analyze the detectability using quantum Fisher information. The enhanced detectability demonstrates the advantages of cylindrical symmetric gravitational waves.
We investigate the entanglement harvesting protocol within the context of cylindrical gravitational waves given first by Einstein and Rosen, focusing on the interactions between non-relativistic quantum systems and linearized quantum gravity. We study how two spatially separated detectors can extract entanglement from the specific spacetime in the presence of gravitational waves, which provides a precise quantification of the entanglement that can be harvested using these detectors. In particular, we obtain the relation between harvested entanglement and the distance to wave sources that emits gravitational waves and analyze the detectability using quantum Fisher information. The enhanced detectability demonstrates the advantages of cylindrical symmetric gravitational waves.
Published:
Abstract:
This paper investigates the neutrino transition magnetic moment in the
\begin{document}$ U(1)_X $\end{document}
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SSM.
\begin{document}$ U(1)_X $\end{document}
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SSM is the
\begin{document}$ U(1) $\end{document}
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extension of Minimal Supersymmetric Standard Model (MSSM) and its local gauge group is extended to
\begin{document}$ SU(3)_C\times SU(2)_L \times U(1)_Y\times U(1)_X $\end{document}
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. To obtain this model, three singlet new Higgs superfields and right-handed neutrinos are added to the MSSM, which can explain the results of neutrino oscillation experiments. The neutrino transition magnetic moment is induced by electroweak radiative corrections. By applying effective Lagrangian method and on-shell scheme, we study the associated Feynman diagrams and the transition magnetic moment of neutrinos in the model. We fit experimental data for neutrino mass variances and mixing angles. Based on the range of data selection, the influences of different sensitive parameters on the results are analysed. The numerical analysis shows that many parameters have an effect on the neutrino transition magnetic moment, such as
\begin{document}$ g_X $\end{document}
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,
\begin{document}$ M_2 $\end{document}
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,
\begin{document}$ \mu $\end{document}
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,
\begin{document}$ \lambda_H $\end{document}
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and
\begin{document}$ g_{YX} $\end{document}
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. For our numerical results, the order of magnitude of
\begin{document}$ \mu_{ij}^M/\mu_B $\end{document}
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is around
\begin{document}$ 10^{-20} $\end{document}
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\begin{document}$ \sim $\end{document}
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\begin{document}$ 10^{-19} $\end{document}
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.
This paper investigates the neutrino transition magnetic moment in the
Published:
Abstract:
We investigate the soft behavior of the tree-level Rutherford scattering processes mediated viat-channel one-graviton exchange. We consider two types of Rutherford scattering processes,e.g., a low-energy massless structureless projectile (up to spin-1) hits a static massive composite particle carrying various spins (up to spin-2), and a slowly-moving light projectile hits a heavy static composite target. The unpolarized cross sections in the first type are found to exhibit universal forms at the first two orders in
\begin{document}$ 1/M $\end{document}
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expansion, yet differ at the next-to-next-to-leading order, though some terms at this order still remain universal or depend on the target spin in a definite manner. The unpolarized cross sections in the second type are universal at the lowest order in projectile velocity expansion and through all orders in
\begin{document}$ 1/M $\end{document}
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, independent of the spins of both projectile and target. The universality partially breaks down at relative order-
\begin{document}$ v^2/M^2 $\end{document}
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, albeit some terms at this order still depend on the target spin in a specific manner.
We investigate the soft behavior of the tree-level Rutherford scattering processes mediated viat-channel one-graviton exchange. We consider two types of Rutherford scattering processes,e.g., a low-energy massless structureless projectile (up to spin-1) hits a static massive composite particle carrying various spins (up to spin-2), and a slowly-moving light projectile hits a heavy static composite target. The unpolarized cross sections in the first type are found to exhibit universal forms at the first two orders in
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Abstract:
We investigate the bound-state equations in two-dimensional QCD in the
\begin{document}$ N_c\to \infty $\end{document}
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limit. We consider two types of hadrons, an exotic "meson" (which is composed of a bosonic quark and a bosonic anti-quark), and an exotic "baryon" (composed of a fermionic quark and a bosonic antiquark). Using the Hamiltonian operator approach, we derive the corresponding bound-state equations for both types of hadrons from the perspectives of the light-front quantization and equal-time quantization, and confirm the known results. We also present a novel diagrammatic derivation for the exotic "meson" bound-state equation in the equal-time quantization. The bound-state equation for the exotic baryons in the equal-time quantization in two-dimensional QCD is new. We also numerically solve various bound-state equations, obtain the hadron spectrum and the bound-state wave functions of the lowest-lying states. We explicitly demonstrate the pattern that as the hadron is boosted to the infinite-momentum frame, the forward-moving bound-state wave function approaches the corresponding light-front wave function.
We investigate the bound-state equations in two-dimensional QCD in the
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We present a family of exact, singularity-free solutions describing the collapse of baryonic matter characterized by a barotropic equation of state whose coefficient
\begin{document}$ \alpha(r,v) $\end{document}
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varies in both radius and time. By matching these interior solutions to the Husain exterior metric, we obtain a self-consistent, dynamical spacetime representing a regular black hole. Although the pressure profile of our models grows with radius and eventually violates the dominant energy condition beyond a critical surface-necessitating an external junction to ensure a globally well-defined spacetime-the interior solution remains non-singular throughout the collapse. We further analyze the optical properties of these regular black holes and find that both the photon sphere radius and the corresponding shadow radius increase monotonically as the local equation of state parameterαis raised. Moreover, the matching interface between the interior and exterior metrics naturally suggests a phase transition in the collapsing fluid, which can postpone the formation of an apparent horizon. Taken together, our results not only highlight novel physical features of horizon formation in regular collapse models but also identify characteristic shadow signatures that could be tested by future observations.
We present a family of exact, singularity-free solutions describing the collapse of baryonic matter characterized by a barotropic equation of state whose coefficient
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Abstract:
Axion-like particles (ALPs) produced via the Primakoff process in the cores of Galactic core-collapse supernovae (SNe) could convert into MeV-energyγ-rays through interactions with the Milky Way’s magnetic field. To evaluate the detection prospects for such signals, we perform sensitivity projections for next-generation MeV telescopes by combining hypothetical instrument responses with realistic background estimates. Our analysis incorporates detailed simulations of the expected ALP flux from nearby SNe, the energy-dependent conversion probability in Galactic magnetic fields, and the telescope’s angular/energy resolution based on advanced detector designs. Background components are modeled using data from current MeV missions and extrapolated to future sensitivity regimes. Our simulations demonstrate that next-generation telescopes with improved effective areas and energy resolution could achieve sensitivity to photon-ALP couplings as low as
\begin{document}$ g_{a\gamma} \approx 1.61 \times 10^{-13}\; \mathrm{GeV}^{-1} $\end{document}
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for ALP masses
\begin{document}$ m_a \lesssim 10^{-9}\; \mathrm{eV} $\end{document}
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in Galactic Center. These results indicate that future MeV missions will probe unexplored regions of ALP parameter space, with conservative estimates suggesting they could constrain
\begin{document}$ g_{a\gamma} $\end{document}
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values two orders of magnitude below current astrophysical limits. Such observations would provide the most stringent tests to date for axion-like particles as a dark matter candidate in the ultra-light mass regime.
Axion-like particles (ALPs) produced via the Primakoff process in the cores of Galactic core-collapse supernovae (SNe) could convert into MeV-energyγ-rays through interactions with the Milky Way’s magnetic field. To evaluate the detection prospects for such signals, we perform sensitivity projections for next-generation MeV telescopes by combining hypothetical instrument responses with realistic background estimates. Our analysis incorporates detailed simulations of the expected ALP flux from nearby SNe, the energy-dependent conversion probability in Galactic magnetic fields, and the telescope’s angular/energy resolution based on advanced detector designs. Background components are modeled using data from current MeV missions and extrapolated to future sensitivity regimes. Our simulations demonstrate that next-generation telescopes with improved effective areas and energy resolution could achieve sensitivity to photon-ALP couplings as low as
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Abstract:
The Bayesian Neural Network (BNN) has been widely used to study nuclear physics in recent years. In this study, a BNN is applied to optimize seven theoretical nuclear mass models, including six global models and one local model. The accuracy of these models in describing and predicting masses of nuclei with both the proton number and the neutron number greater than or equal to 8 has been improved effectively for two kinds of numerical experiments, especially for the liquid drop model and the relativistic mean-field theory, whose root mean squared deviations (RMSDs) of describing (predicting) nuclear masses have been reduced by 81.5% ~ 90.6% (66.9% ~ 84.2%). Additionally, the relatively stable RMSDs as nuclei move away from theβ-stability line and the good agreement with experimental single-neutron separation energies further confirm the reliability of the BNN.
The Bayesian Neural Network (BNN) has been widely used to study nuclear physics in recent years. In this study, a BNN is applied to optimize seven theoretical nuclear mass models, including six global models and one local model. The accuracy of these models in describing and predicting masses of nuclei with both the proton number and the neutron number greater than or equal to 8 has been improved effectively for two kinds of numerical experiments, especially for the liquid drop model and the relativistic mean-field theory, whose root mean squared deviations (RMSDs) of describing (predicting) nuclear masses have been reduced by 81.5% ~ 90.6% (66.9% ~ 84.2%). Additionally, the relatively stable RMSDs as nuclei move away from theβ-stability line and the good agreement with experimental single-neutron separation energies further confirm the reliability of the BNN.
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Abstract:
Elasticα-12C scattering for
\begin{document}$ l=2 $\end{document}
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andE2 transition of radiativeαcapture on12C,12C(α,γ)16O, are studied in cluster effective field theory. Due to the problem in fixing the asymptotic normalization coefficient (ANC) of the subthreshold
\begin{document}$ 2_1^+ $\end{document}
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state of16O, equivalently, the effective range parameters of the
\begin{document}$ 2_1^+ $\end{document}
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state, from the elastic scattering data, we introduce the conditions that lead to a large value of the ANC. In addition,d-wave phase shift data of the elastic scattering up to theαenergy,
\begin{document}$ E_\alpha=10 $\end{document}
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MeV, which contain resonant
\begin{document}$ 2_4^+ $\end{document}
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state of16O, are also introduced in the study. Applying the conditions, the parameters of theSmatrix of the elastic scattering for
\begin{document}$ l=2 $\end{document}
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are fitted to the phase shift data, and the fitted parameters are employed in the calculation of astrophysical
\begin{document}$ S_{E2} $\end{document}
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factor of12C(α,γ)16O; we extrapolate the
\begin{document}$ S_{E2} $\end{document}
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factor to the Gamow-peak energy,
\begin{document}$ E_G=0.3 $\end{document}
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MeV. We find that the conditions lead to significant effects in the observables of the
\begin{document}$ 2_4^+ $\end{document}
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state of16O and the estimate of the
\begin{document}$ S_{E2} $\end{document}
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factor at
\begin{document}$ E_G $\end{document}
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and confirm that the ANC of the
\begin{document}$ 2_1^+ $\end{document}
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of16O cannot be determined by the phase shift data for
\begin{document}$ l=2 $\end{document}
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.
Elasticα-12C scattering for
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Abstract:
This study utilizes the PYTHIA8 Angantyr model to systematically investigate the effects of three nucleons correlation
\begin{document}$C_{n^2p}$\end{document}
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on the light nuclei yield ratio
\begin{document}$N_tN_p/N_d^2$\end{document}
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in Au+Au collisions at
\begin{document}$\sqrt{s_{\mathrm{NN}}}$\end{document}
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= 7.7, 11.5, 14.5, 19.6, 27, 39, 62.4, and 200 GeV. The analysis explores this property across different rapidity ranges, collision centralities, and collision energies, while also examining the roles of multi-parton interactions (MPI) and color reconnection (CR) mechanisms. The results show that the light nuclei yield ratio remains stable with changes in rapidity coverage and collision centrality but slightly increases with rising collision energy. The impact of CR on the light nuclei yield ratio depends entirely on the presence of MPI; when MPI is turned off, CR has no effect. Additionally, the three-nucleon correlation, enhances the light nuclei yield ratio in both central and peripheral collisions. However, the non-monotonic energy dependence observed in experiments, the peak at
\begin{document}$\sqrt{s_{\mathrm{NN}}}=20\sim30$\end{document}
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GeV reported by the STAR experiment, cannot be explained by the Angantyr model due to its lack of key mechanisms related to the quark-gluon plasma (QGP). Nevertheless, the Angantyr model serves as an important baseline for studying collision behaviors in the absence of QGP effects.
This study utilizes the PYTHIA8 Angantyr model to systematically investigate the effects of three nucleons correlation
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We present a comprehensive theoretical approach for describing the amplitude of the processes
\begin{document}$ J/\psi \to \gamma ab $\end{document}
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, whereaandbare pseudoscalar mesons. Our approach systematically incorporates: final-state rescattering between the pseudoscalar pair
\begin{document}$ ab $\end{document}
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, contributions from intermediate resonances and coupled-channel effects via rescattering ofawith a intermediate state
\begin{document}$ \bar{X} $\end{document}
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(which subsequently decays to
\begin{document}$ \gamma b $\end{document}
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). The formalism ensures unitarity in the two-body rescattering amplitude and dynamically dressed couplings between resonances and pseudoscalar pair. Using a toy model, we perform numerical calculations and demonstrate that coupled-channel effects significantly influence the lineshape of the invariant mass spectrum of the final states. These findings highlight the necessity of including coupled-channel dynamics in interpretations of
\begin{document}$ J/\psi $\end{document}
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radiative decays.
We present a comprehensive theoretical approach for describing the amplitude of the processes
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A future
\begin{document}$ e^+e^- $\end{document}
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collider could run at the Z-pole to perform important electroweak (EW) precision measurements, while such a run may not be viable for a future muon collider. This however can be compensated by the measurements of other EW processes, taking advantage of the high energy and large luminosity of the muon collider. In this paper, we consider the measurements of the vector boson fusion processes of
\begin{document}$ WW/WZ/W\gamma $\end{document}
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to a pair of fermions (along with a
\begin{document}$ \nu_{\mu}\bar{\nu}_{\mu} $\end{document}
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or
\begin{document}$ \nu_{\mu}\mu^+/\bar{\nu}_{\mu}\mu^- $\end{document}
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pair) at a high-energy muon collider and study their potential in probing the EW observables. We consider two run scenarios for the muon collider with center-of-mass energy of 10 TeV and 30 TeV, respectively, and focus on the processes involving
\begin{document}$ f=b,c,\tau $\end{document}
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and the dimension-6 operators that directly modify the corresponding fermions coupling to the
\begin{document}$ Z/W $\end{document}
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bosons. The invariant mass distribution of the
\begin{document}$ f\bar{f} $\end{document}
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pair helps to separate the events from the
\begin{document}$ Z/W $\end{document}
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resonance and the high-energy ones, while the polar angle of the outing fermion also provides additional information. By performing a chi-squared analysis on the binned distributions and combining the information from theWWand
\begin{document}$ WZ/W\gamma $\end{document}
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fusion processes, all relevant Wilson coefficients can be constrained simultaneously. The precision surpasses the current EW measurement constraints and is even competitive with future
\begin{document}$ e^+e^- $\end{document}
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colliders. Our analysis can be included in a more complete framework which is needed to fully determine the potential of muon colliders in EW precision measurements.
A future
Published:
, doi:10.1088/1674-1137/ad8ec2
Abstract:
The direct CP asymmetry in the weak decay process of hadrons is commonly attributed to the weak phase of the CKM matrix and the indeterminate strong phase. We propose a method to generate a significant phase difference through the interference betweenρandωmesons, taking into account the G-parity allowed decay process of
\begin{document}$\omega \rightarrow \pi^{+}\pi^{-}\pi^{0}$\end{document}
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and the G-parity-suppressed decay process of
\begin{document}$\rho^{0} \rightarrow \pi^{+}\pi^{-}\pi^{0}$\end{document}
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inBmeson decays. This interference can lead to notable changes in the CP asymmetry within the interference region. Additionally, we calculate the integral results for different phase space regions of the four-body decay process. We hope that our work provides valuable theoretical guidance for future experimental investigations on CP asymmetry in these decays.
The direct CP asymmetry in the weak decay process of hadrons is commonly attributed to the weak phase of the CKM matrix and the indeterminate strong phase. We propose a method to generate a significant phase difference through the interference betweenρandωmesons, taking into account the G-parity allowed decay process of
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