I'll review the recent progresses and highlights in the following topics of charmed baryon physics: (i) spin-parity quantum numbers of excited charmed baryon resonances, (ii) lifetimes of singly and doubly charmed baryons, (iii) nonleptonic weak decays of charmed baryons, (iv) charm-flavor-conserving hadronic decays, and (v) semi-leptonic decays.
There have been many progresses on weak decays of charmed baryons from theoretical and experimental sides. In this talk, I will give an overview of recent lattice QCD efforts, and will mostly focus on the $\Xi_c \to \Xi$ transitions, which are based on the newly generated lattice configurations.
We report new measurements on charmed baryon spectroscopy and decays performed using data collected by the Belle experiment at the KEKB asymmetric-energy $e^{+}e^{-}$ collider. The talk covers the test of lepton-flavor universality conducted in $\Omega_{c} \to \Omega \ell \nu$, and studies involving other $\Lambda_c$ and $\Xi_c$ decays. Other recent results on charmed baryons from Belle are...
The Fermilab Muon $g-2$ Experiment aims to make precise measurements of the anomalous magnetic moment ($a_{\mu}$) of the muon. The first measurement of the experiment is $3.3\sigma$ larger than the Standard Model (SM) prediction. The measurement is in good agreement with the previous result with improved precision. The uncertainty of the measurement is $0.46~ppm$ which gives the most precise...
A short overview of the effective-field-theory approach for analysing the doubly heavy near-threshold states in the experimental line shapes is presented. Several applications to the LHCb pentaqurks, the bottomoniumlike states $Z_b(10610)$ and $Z_b(10650)$, and the $T_{cc}^+$ are discussed. The role of the one-pion exchange in the effective hadronic potential on the results is reviewed.
The Super Charm-Tau Factory (SCTF) is a proposed $e^+e^-$ collider operating in the c.m. energy range from 3 to $7~\rm GeV$ with a luminosity of $10^{35} cm^{-2} s^{-1}$, two orders of magnitude more than that of BEPC-II, the existing collider operating in the same energy range. The SCT experiment will provide a comprehensive study of charmed and light hadrons and a tau lepton, aimed at deep...
The proposed STCF is a symmetric electron-positron beam collider designed to provide $e^+e^-$ interactions at a centerof-mass energy from 2.0 to $7.0~\rm GeV$. The peaking luminosity is expected to be $0.5\times 10^{35} cm^{-2}s^{-1}$. The energy region of STCF covers the pair production thresholds for $\tau$-leptons, charmed meson & baryons, and all of the strange hyperons. STCF is expected...
Many new exotic hadrons, that do not fit into the existing naming scheme for hadrons, have been discovered over the past few years. A new scheme is set out, extending the existing protocol, in order to provide a consistent naming convention for these newly discovered states, and other new hadrons that may be discovered in future.
At BESIII, the electromagnetic form factors (EMFFs) and the pair production cross sections of various baryons have been studied. The proton EMFF ratio |GE/GM| is determined precisely and line-shape of |GE| is obtained for the first time. The recent results of neutron EMFFs at BESIII show great improvement comparing with previous experiments. Cross sections of various baryon pairs ($\Lambda$,...
The large data sample recorded by the Belle experiment at the KEKB asymmetric-energy $e^{+} e^{-}$ collider is very useful for studying light baryons or mesons. We report the observation of $\Omega(2012)^{-} \to \Xi(1530)^0 K^-$ as well as of a narrow structure in $\Lambda^{+}_{c} \to p K^-\pi^+$. We also discuss about the determination of resonant parameters of $\phi(1680)$ using the...
An exotic state with $J^{PC}=1^{-+}$, denoted by $\eta_1(1855)$, was observed by BESIII collaboration recently in $J/\psi \to \gamma \eta\eta^\prime$. The fact that its mass is just below the threshold of $K\bar{K}_1(1400)$ stimulates us to investigate whether this exotic state can be interpreted as a $K\bar{K}_1(1400)+ c.c.$ {molecule or not}. Using the one boson exchange model, we show that...
We present the first theoretical prediction of the production rate of $1^{-+}$ light hybrid meson $\eta_1$ in $J/\psi$ radiative decays. In the $N_f = 2$ lattice QCD formalism with the pion mass $m_\pi\approx 350$ MeV, the related electromagnetic multipole form factors are extracted from the three-point functions that involve necessarily quark annihilation diagrams, which are calculated...
The Muon g-2/EDM experiment at J-PARC (E34) aims to measure muon g-2 and EDM with different approach from FNAL and BNL Muon g-2 experiments. The technical design of the experiment has been completed, and construction of the experiment has started. The budget is being requested to start the data taking in 2027. In the first phase, the measurement of g-2 with a precision of 0.45 ppm is expected...
The latest measurement of the muon g-2 announced at Fermilab exhibits a 4.2$\sigma$ discrepancy from the currently accepted Standard Model prediction. The main source of uncertainty on the theoretical value is represented by the leading order hadronic contribution $a_{\mu}^{HLO}$, which is traditionally determined through a data-driven dispersive approach. A recent calculation of...
The CERN MUonE experiment aims at a new and independent determination of the leading order correction to the muon anomalous magnetic moment, through a high-precision measurement of the hadronic contribution to the running of the QED coupling constant in elastic $\mu e\to\mu e$ events, by exploiting 160 GeV muons scattering on atomic electrons. The required precision in the measurement of the...
Belle II offers unique possibilities for the discovery and interpretation of exotic multiquark combinations to probe the fundamentals of QCD. This talk present recent results from a scan above the $\Upsilon(4S)$ resonance.
BESIII has collected $4.5 fb^{-1}$ of $e^+e^-$ collision data between 4.6000 and $4.6999~\rm GeV$. This unique data offers ideal opportunity to determine absolute branching fractions of $\Lambda_c^+$ decays. We will report the first observation of $\Lambda_c^+ \to n\pi^+$. Meanwhile, we will report prospect on the studies of semileptonic and the other hadronic decays of $\Lambda_c^+$ in the...
BESIII has collected 2.93 and $6.32 fb^{-1}$ of $e^+e^-$ collision data samples at 3.773 and $4.178-4.226~\rm GeV$, respectively. We will report the observation of a new $a_0$ resonance and amplitude analyses of $D_s \to K_S K^+ \pi^0$, $K_S K_S \pi^+$, $\pi^+ \pi^0 \eta^\prime$, $KK3\pi$, $K \pi \pi \pi^0$, and $\pi^+\pi^0\pi^0$. We will also report the transverse polarization determination...
BESIII has collected 2.93 and $6.32~fb^{-1}$ of $e^+e^-$ collision data samples at 3.773 and $4.178-4.226~\rm GeV$, respectively. We will report precision measurements of $f_{Ds}$, $|V_{cs}|$ and test of lepton flavor universality by studying the leptonic decays of $D_s \to l^+\nu$ with $\tau^+ \to \rho^+\nu$, $\pi^+\nu$, and $e^+\nu\nu$. We will also report the studies of $D_s \to \pi^0\pi^0...
With the large datasets on $e^+e^-$-annihilation at the $J/\psi$ and $\psi(3686)$ resonances collected at the BESIII experiment, multi-dimensional analyses making use of polarization and entanglement can shed new light on the production and decay properties hyperon-antihyperon pairs. In a series of recent studies performed at BESIII, significant transverse polarization of the (anti)hyperons...
The improvement of the standard model (SM) prediction of the muon anomalous magnetic moment $(g-2)$ is of utmost importance in view of the recent and upcoming experimental results from the FNAL E989 experiment. The BESIII collaboration is strongly involved in providing valuable inputs towards a strong reduction of the dominant sources of uncertainty to the SM calculation: the hadronic vacuum...
We report studies of hadrons performed using two-photon processes at Belle. In particular, the two-photon process $\gamma\gamma \to \gamma\psi(2S)$ is studied for the first time in an effective center-of-mass energy ranging from 3.7 to 4.2 GeV. Evidence is established for a structure in the $\gamma\psi(2S)$ invariant-mass distribution around 3920 MeV/$c^{2}$, and hint is found for another...
We present a parameter-free prediction of the two-photon transitions of the charmonium system $[c\bar c] \to \gamma^*\gamma$ in a relativistic light-front formalism. The use of light-front formulation automatically takes into account the large-$Q^2$ behavior of the process as predicted by pQCD. Furthermore, the relativistic nature of the light-front dynamics provides a reliable access to the...
We accomplish the complete two-loop computation of the leading-twist contribution to the photon-pion transition form factor $\gamma \gamma^∗ \to \pi $ by applying the hard-collinear factorization theorem together with modern multi-loop techniques. The resulting predictions for the form factor indicate that the two-loop perturbative correction is numerically important. We also demonstrate that...
A recent lattice QCD calculation of two-photon contributions to the muonic hydrogen Lamb shift will be reported.
The world’s largest sample of $J/\psi$ events accumulated at the BESIII detector offers a unique opportunity to investigate $\eta$ and $\eta^′$ physics via two body $J/\psi$ radiative or hadronic decays. In recent years the BESIII experiment has made significant progresses in $\eta/\eta^′$ decays. A selection of recent highlights in light meson spectroscopy at BESIII are reviewed in this...
Using $10.1 \times 10^9~ J/\psi$ events produced by the Beijing Electron Positron Collider (BEPCII) at a center-of-mass energy $\sqrt{s} = 3.097~\rm GeV$ and collected with the BESIII detector, we present a search for the rare semi-leptonic decay $J/\psi \to D^-e^+\nu_e + c.c.$ No excess of signal above background is observed, and an upper limit on the branching fraction $\mathcal{B}(J/\psi...
Based on analyzing $4.45~fb^{-1}$ data taken at seven center-of-mass energies ranging from 4.600 to $4.699~\rm GeV$ with the BESIII detector at the BEPCII collider, we measure the branching fractions for $\Lambda_c^+ \to \Sigma^+ + hadrons$ relative to $\Lambda_c^+ \to \Sigma^+ \pi^+ \pi^-$. By quoting the world average branching fraction of $\Lambda_c^+ \to \Sigma^+ \pi^+ \pi^-$, their...
With the worldly largest $\psi(2S)$ samples collected at BEESIII, systematic studies of the decays of $\eta_c(2S)$ are performed. As an example, the observation of the decay $\eta_c(2S) \to 3 (\pi^+ \pi^-)$ will be reported in this talk. Based on the 450M $\psi(2S)$ samples, the mass and width of $h_c$ are updated as well as the branching fraction of $\psi(2S) \to \pi^0 h_c$. In this talk,...
At BESIII, the lineshapes of $e^+e^- \to \phi \eta^\prime$, $\phi \eta$, $KK$, $\omega \pi^0$, $\eta \pi\pi$, $\omega \pi\pi$ are measured from 2.0 to $3.08~\rm GeV$, where resonant structures are observed in these processes. Multiple lineshapes of intermediate state are obtained by a partial wave analysis of $e^+e^- \to K^+ K^- \pi^0 \pi^0$, $K^+K^- \pi^0$ and the structures observed provide...
In this work, we interpret the newly $\eta_1(1855)$ resonance with exotic $J^{PC}=1^{-+}$ quantum numbers in the $I=0$ sector, reported by BESIII collaboration, as a dynamically generated state from the interaction between the lightest pseudoscalar mesons and vector mesons. The interaction is derived from the lowest order chiral Lagrangian from which the Weinberg-Tomozawa term is obtained,...
Based on a sample of $4.4 fb^{-1}$ of $e^+e^-$ annihilation data collected in the energy region between $4.6~\rm GeV$ and $4.7~\rm GeV$ with the BESIII detector at BEPCII, two singly Cabibbo-suppressed decays $\Lambda_c^+ \to \Sigma^0 K^+$ and $\Lambda_c^+ \to \Sigma^+ K_S^0$ are studied. New determinations of the BFs of $\Lambda_c \to \Sigma K$ decays, in particular the mode and $\Lambda_c^+...
Based on $4.4 fb^{-1}$ of $e^+e^-$ annihilation data collected in the energy region between $4.6~\rm GeV$ and $4.7~\rm GeV$ with the BESIII detector at the BEPCII collider, we search for semi-leptonic decays $\Lambda_c^+ \to \Lambda \pi^+ \pi^- e^+ \nu_e$ and $\Lambda_c^+ \to p K_S \pi^- e^+ \nu_e$, using double tag technique. The measurement of $\Lambda_c^+ \to \Lambda^* e^+ \nu_e$ is...
The isospin breaking and radiative decay widths of the positive-parity charm-strange mesons, $D^{∗}_{s0}$ and $D_{s1}$, and their predicted bottom-strange counterparts, $B^{∗}_{s0}$ and $B_{s1}$, as hadronic molecules are revisited. This is necessary, since the $B^{∗}_{s0}$ and $B_{s1}$ masses used in (Cleven et al., Eur Phys J A 50:149, 2014) were too small, in conflict with the heavy quark...
In this paper, we present a preliminary study of $CP$ violation effect of $K^{0}-\bar{K}^{0}$ system in $J/\psi$ decay. The $CP$ violation parameters $\eta_{+-}$ and $\eta_{00}$ as well as their corresponding phase $\phi_{+-}$ and $\phi_{00}$ can be determined by the difference of the time-dependent decay rates between $K^{0}$ and $\bar{K}^{0}$ produced from $J/\psi \rightarrow...
In the Standard Model, Flavor-changing-neutral-current (FCNC) in quark sector is predicted at loop level. In the lepton sector, the lepton-flavor-violation (LFV) was evident after the discovery of neutrino oscillation. In the SM, even considering the tiny masses and oscillation of neutrinos, the predicted decay rate for charged-lepton-flavor-violation (cLFV), such as muon-electron conversion,...
Based on $e^+e^-$ collision samples corresponding to an integrated luminosity of $4.4~ fb^{-1}$ collected with BESIII detector at center-of-mass energies between $4.6~\rm GeV$ to $4.7~\rm GeV$, the first partial wave analysis of the charmed baryonic decay $\Lambda_c^+ \to \Lambda \pi^+ \pi^0$ is performed. From the analysis results, the decays of $\Lambda_c^+ \to \Lambda \rho(770)^+$ and...
We investigate the process $B\to \bar{D}D_s \pi$ via several rescattering processes. It is shown that the triangle singularity (TS) peak around the $D^*K^*$ threshold generated from the $\chi_{c1}K^* D^*$ loop is relatively narrow, which may simulate the resonance-like structure $T_{c\bar{s}}(2900)$ recently observed by LHCb in the $D_s\pi$ spectrum. However, the TS peak around the $D_s^*\rho$...
We present a search for the lepton flavor violating decay $J/\psi \to e \mu$ using $8.998\times 10^9~ J/\psi$ events collected with the BESIII detector at the BEPCII $e^+e^-$ storage ring. No excess of signal above background is observed; we therefore set an upper limit on the branching fraction of $J/\psi \to e \mu < 4.5\times 10^{-9}$ at the 90% confidence level. Improving the previous best...
The large data sample accumulated by the Belle experiment at the KEKB asymmetric-energy $e^{+}e^{-}$ collider provides a unique opportunity to study charmonium(-like) states. We report new results on the $X(3872)$ decays to $J/\psi\omega$ and $\pi^+\pi^-\pi^0$ final states, as well as other studies involving charmonia. We also present a search for double-heavy tetraquark states...
In the last two decades plenty of new so-called XYZ-states in the charmonium mass region have been discovered, many of which are still under investigation. Amonge those, the $\chi_{c1}(3872)$ a.k.a. $X(3872)$ is the oldest and one of the most puzzling states. To identify the nature, in particular the exact line shape of the object needs to be determined. While current experiments such as LHCb...
Last year, the Muon g-2 experiment at Fermilab reported a value for the muon magnetic moment that disagrees with the theoretical SM prediction by 4.2 standard deviations. The potential to confirm the presence of a BSM muon interaction beyond 5 standard deviations rests heavily on improving the SM predictions for the muon magnetic moment, which is entirely dependent on improving evaluations of...
Fermilab has just announced a new experimental result for muon g-2. The statistical uncertainty of the new result is similar to the previous BNL result and the central value is consistent. The combined value is now 4.2 standard deviations away from the Standard Model prediction. For the Standard Model prediction, the two hadronic contributions, HVP (hadronic vacuum polarization) and HLbL...
Many scenarios of physics beyond the Standard Model predict dark sectors containing new particles interacting only feebly with ordinary matter. Collider searches for these scenarios have largely focused on identifying signatures of new mediators, leaving much of the dark sector structure unexplored. We investigate the existence of a light dark-matter bound state, the darkonium, $\Upsilon_D$),...
Belle has unique reach for a broad class of models that postulate the existence of dark matter particles with MeV—GeV masses. This talk presents recent world-leading physics results from Belle II searches for dark Higgstrahlung. ALPs and Z'.
The BESIII experiment is a symmetric $e^+e^-$ collider operating at c.m. energy from 2 to $4.95~\rm GeV$. With the world’s largest data set of $J/\psi$ (10 Billion), $\psi(2S)$ (2.6 Billion), and about $25 fb^{-1}$ scan data from 3.77 to $4.95~\rm GeV$, we are able search various dark sectors produced in $e^+e^-$ annihilation and meson decay processes. In this talk, we report the recent search...
It is shown that all predictions for the light scalars, based on their four-quark nature, are supported by experiment. The future research program is outlined also.
In this talk, recent measurements of the cross-section of $e^+ e^- \to \pi^+ \pi^- J/\psi$, $e^+ e^- \to K^+ K^- J/\psi$, and $e^+ e^- \to \pi^+ \pi^- \psi_2(3823)$ at BESIII will be reported. It will include the new decay modes of the well-known resonance, such as $Y(4230)$, and the new observed structures that strongly coupled to these channels.
The CMD-3 experiment at the VEPP-2000 collider is aimed to measure the cross-sections and dynamics of the exclusive modes of $e^+ e^- \to hadrons$ reactions in the system energy range from 0.32 GeV to 2 GeV.
The experiment has collected $600~pb^{-1}$. In this report we will discuss current status and results obtained by the collaboration of the CMD-3 experiment.
A special scan for data collection at the $p\bar{p}$ and $n\bar{n}$ thresholds has been performed at the VEPP2000 $e^+e^-$ collider. About 10 $pb^{-1}$ per point were collected by the SND and CMD-3 detectors with about 1 MeV step, comparable with the energy spread of the c.m. energy. Energy stability at the level 0.1 MeV was continuously monitored by the back-scattering laser system. We...
As an iso-spin partner of the charged $Z_{cs}(3985)$ state, the evidence for a neutral near-threshold structure in the $K_s$ recoil-mass spectra in $e^+ e^- \to K_s (D_s^- D^{*+} + D_s^{*-} D^+)$ will be reported. Also, there will be report of searching for $X(3872) \to \pi^0 \chi_{c0}$ and $X(3872) \to \pi \pi \chi_{c0}$ at BESIII. For the $Y$ state, the cross-section measurements of the $e^+...
Measurements of the branching ratios of conversion decays are necessary to test the vector dominance model and estimate the background in the study of quark-gluon plasma. An important source of information about the physical processes occurring in a quark-gluon plasma is the production of dileptons, in particular, the production of electron-positron pairs. In experiments, the measured number...
Using the $1.32~pb^{-1}$ statistics collected at the $J/\psi$ peak with the KEDR detector at the VEPP-4M $e^+e^-$ collider, we measured the branching fractions of $J/\psi$ meson decays to the final states $2(\pi^+\pi^-)\pi^0$, $K^+K^-\pi^+\pi^-\pi^0$, $2(\pi^+\pi^-)$ and $K^+K^-\pi^+\pi^-$. The results obtained for the decays $J/\psi \to 2(\pi^+\pi^-)\pi^0$, $J/\psi \to K^+K^- \pi^+\pi^-\pi^0$...
KLOE and KLOE-2 data (almost $8~fb^{-1}$) constitute a unique sample, rich in physics, and the largest dataset ever collected at an electron-positron collider operating at the $\phi$ peak resonance.
In total it corresponds to the production of about 24 billion $\phi$ mesons, whose decays include about 8 billion pairs of neutral $K$ mesons and about 300 million $\eta$ mesons.
A wide...
The excitation spectrum of light mesons; which are composed of up, down, and strange quarks; allows us to study QCD at low energies. While the non-strange light-meson spectrum is already mapped out rather well, many predicted strange mesons have not yet been observed experimentally and many potentially observed states still need further confirmation. Hence, the strange-meson spectrum still...
The BESIII experiment has collected 2.6B $\psi(2S)$ events and 10B $J/\psi$ events. The huge data sample provide an excellent chance to search for rare processes in charmonium decays. In this talk, we report the recent search for $J/\psi \to \phi e^+e^-$, $D^-e^+\nu_e$. The big charmonium sample also produce millions of hyperons, which is used to study the weak decay of $\Sigma^- \to...
The theoretical description of the dynamics behind baryonic decays of heavy flavoured particles is still very challenging. The branching ratio enhancement in multibody decays and the suppression of the branching fractions to two-body final states are interesting features of these processes. To better understand their underlying dynamics, more precise measurements are needed. In this...
This talk presents a model independent search for an additional heavy, mostly sterile, neutral lepton (HNL) which is capable of mixing with the Standard Model tau neutrino with a mixing strength of $|\tau 4|2$, corresponding to the square of the extended Pontecorvo–Maki–Nakagawa–Sakata (PMNS) matrix element. HNLs are hypothetical particles predicted by many beyond Standard Model theories,...
The ratios $R_{\tau/P}\equiv \Gamma(\tau\to P \nu_\tau[\gamma])/\Gamma(P\to \mu \nu_\mu[\gamma]) (P=\pi, K)$ provide sensitive tests of lepton universality $|g_\tau/g_\mu|=1$ and are a useful tool for new physics searches. We improve previous computations of the corresponding radiative corrections, within Chiral Perturbation Theory with resonances, complying with known QCD limits. We find...
The HFLAV tau branching fraction fit results are used to compute lepton universality tests and Vus, using the recently published radiative corrections for the tau hadronic branching fractions. The HFLAV tau fit is included in the HFLAV report that has been recently submitted for publication.
In this contribution, I will present the muonium spectroscopy at J-PARC, and also facility status.
I will first discuss the hadronic contributions to the $\tau \to \pi \pi \gamma \nu$ process. Distinct hadron effects are revealed in different two-particle invariant mass spectra. I will then focus on the T-odd asymmetry from the radiative two-pion decays and intriguing non-vanishing asymmetry distributions are predicted, which may provide useful guidelines to future measurements at Belle-II...
The Spherical Neutral Detector (SND) collects data at the VEPP-2000 $e^+e^-$ collider in Novosibirsk. In this talk we present the latest SND results on study of exclusive processes of $e^+e^-$ annihilation into hadrons at c.m. energies below 2 GeV. In particular, we discuss the measurement of the $e^+e^- \to \pi^+\pi^-$ cross section in the energy range $0.53 - 0.88~\rm GeV$, the measurement...
We will present recent analyses on how lineshape studies can shed light on the nature of several exotic candidates
If the $X(3872)$ or $T_{cc}^+(3875)$ is a weakly bound charm-meson molecule, it can be produced by the creation of $D^\ast \bar D^\ast$ or $D^\ast D^\ast$ at short distances followed by the rescattering of the charm mesons into $X(3872)$ or $T_{cc}^+(3875)$ and a pion or a photon through a triangle loop. A triangle singularity produces narrow peak in the reaction rate in production of...
Recently, many new hadronic states were found that do not fit into the simple constituent-quark model for mesons and baryons. One prominent example is the $a_1(1420)$ signal that was observed by the COMPASS experiment in the $f_0(980)\pi$ $P$-wave with $J^{PC}=1^{++}$ quantum numbers.
Different mechanisms were suggested to explain these signals, one of which is rescattering of...
We present the first lattice QCD calculation of partial decay width from $J/\psi$ to $\gamma\eta$ to confirm that QCD $U_A(1)$ anomaly enhances the coupling of gluons with flavor singlet pseudoscalar mesons. The lattice simulation is carried out using $N_f=2$ lattice QCD gauge configurations at the pion mass $m_{\pi} \approx 350$ MeV. In particular, the distillation method has been utilized to...
In view of a new experiment which is under preparation at VEPP-4M collider at Novosibirsk the results the mass measurements conducted about forty years ago were reanalyzed. The reanalysis includes, when required, radiative corrections, interference effects, use of modern electron's mass value and more accurate numerical calculations. The shift of $\Upsilon(2S)$ mass for some measurements reach...
Outstanding vertexing performance and low-background environment are key enablers of a systematic Belle II program targeted at measurements of charm hadron lifetimes Recent results from measurements of $D^0$ meson, $D^+$ meson and $\Lambda_c$ baryon lifetimes are presented. The results are the most precise to date.
Little Higgs models were proposed as an attractive way of reducing the little hierarchy problem. Their promising LFV phenomenology has been studied (mainly for the Littlest Higgs model with T-parity, LHT, and for the Simplest Little Higgs model, SLH) in the last decade by several groups worldwide. We have recently highlighted the changes with respect to this well-known pattern induced by the...
During the last 15 years the "Radio MontecarLow (“Radiative Corrections and Monte Carlo Generators for Low Energies”) Working Group, see www.lnf.infn.it/wg/sighad/, has been providing valuable support to the development of radiative corrections and Monte Carlo generators for low energy e+e- data and tau-lepton decays. Its operation which started in 2006 proceeded until the last few years...
As one of the hypothetical principles in the Standard Model (SM), lepton flavor universality (LFU) should be measured with a precision as high as possible such that the physics violating this principle can be fully tested. The $Z$ factories at the future $e^-e^+$ colliders provide a great opportunity to perform this task because of their large statistics and high reconstruction efficiencies...
The technique of parity-violating electron scattering, involving measurements of the asymmetry in the scattering of longitudinally polarized electrons off fixed targets, has become increasingly precise over the past three decades. Such asymmetries are sensitive to weak neutral current interactions (mediated by the Z boson) between electrons and quarks, or between two electrons, and can be...
