第十七届TeV工作组学术研讨会

The search of heavy Majorana neutrino is a long-standing topic in the field of high-energy physics and BSM physics. High-energy muon colliders are potentially ideal machines in both energy and precision frontiers. We proposed a clear lepton-number-violating signature through vector boson scattering to search for heavy Majorana neutrino at both ^+ ^− and ^+ ^+ colliders (JHEP 09 (2023) 131,...

PandaX-4T experiment is a deep-underground dark matter direct search experiment that employs a dual-phase time projection chamber with a sensitive volume containing 3.7 tonnes of liquid xenon. Along with a series of exotic dark matter model tests, a blind analysis was applied to the full exposure of PandaX-4T recorded data. In this talk, I will discuss the latest dark matter search results of...

Science Bulletin (accepted) Ref: https://arxiv.org/abs/2306.00641

Results from a wide range of searches targeting different experimental signatures with and without missing transverse momentum ($E^{miss}_T$) are used to constrain a Two-Higgs-Doublet Model (2HDM) with an additional pseudo-scalar mediating the interaction between ordinary and dark matter (2HDM+a). The analyses use up to 139...

We propose a new scenario that both the dark matter freeze-out in the early Universe and its possible annihilation for indirect detection around a supermassive black hole are enhanced by a Breit-Wigner resonance. With the mediator mass larger than the total initial dark matter mass, this annihilation is almost forbidden at late times. Thus, the stringent cosmic microwave background and...

This talk will present the latest search for the non-resonant production of Higgs boson pairs in the $HH\rightarrow b\bar{b}\tau^+\tau^-$ channel. The search is performed using 140 fb$^{-1}$ of proton-proton collisions at a centre-of-mass energy of $13$ TeV recorded by the ATLAS detector at the LHC. The analysis strategy is optimized to probe anomalous values of the Higgs boson ($H$)...

Type II seesaw Leptogenesis

The neutrino electromagnetic properties was first studied by Pauli in his famous letter of proposing the very existence of neutrino. Altough neutrinos are neutral and hence does not have electric charge, it is perfectly OK for them to have electric and magnetic dipole moments as well as charge radius and anapole. Nevertheless, existing terrestrial experiments and celestial observations can...

This talk will present the latest results from ATLAS in the measurement of SM-EWK multiboson production process in the Z$\gamma$+jets final states including the 1st observation of VBS Z$\gamma$+2j at ATLAS. Also the neutral gauge boson coupling BSM phenomena is probed in such final states utilizing LHC-ATLAS Run-2 proton-proton collision dataset (ref: JHEP 07 (2023) 72 & Phys. Lett. B 846...

In this paper, we consider the sterile neutrino portal dark matter with $Z_3$ symmetry. This model further extends the canonical type-I seesaw with a fermion singlet $\chi$ and a scalar singlet $\phi$. Under the $Z_3$ symmetry, the dark sector transforms as $\chi\to e^{i2\pi/3}\chi, \phi\to e^{i2\pi/3}\phi$, while the standard model particles and the sterile neutrino $N$ transform trivially....

Discriminating the Higgs production mechanisms plays a crucial role in directly measuring the couplings of Higgs to gauge bosons for probing the nature of the electroweak symmetry breaking. We propose a novel method to distinguish the Higgs production mechanisms at the LHC by utilizing the jet charge asymmetry of the two leading forward jets in Higgs plus two jets production. This novel...

Heavy neutral gauge boson $Z^\prime$ is proposed in many new physics models. It has rich phenomena at the future muon collider. We study the properties of $Z^\prime$ boson with the process of $\mu^+ \mu^- \rightarrow q \bar{q}$, $\mu^+ \mu^- \rightarrow l^+ l^-$, $\mu^+ \mu^- \rightarrow Z H$ and $\mu^+ \mu^- \rightarrow W^+ W^-$.

In this talk, we explore the potential of probing the inelastic dark matter (DM) model with an extra $(1)_$ gauge symmetry at the Large Hadron Collider, ForwArd Search ExpeRiment and Super Tau Charm Factory. To saturate the observed DM relic density, the mass splitting between two light dark states has to be small enough, and thus leads to some distinctive signatures at these colliders. By...

In this talk, I will present new mass generation mechanisms for axion-like particles (ALP), and discuss the evolution of these ALP in the early universe. I will also show that the observed baryon asymmetry of the universe can be addressed in this mechanism with the help of the spontaneous baryogenesis mechanism.

$\Delta L = 2 $ lepton number violation at the TeV scale connects $0\nu\beta\beta$ decay (intensity frontier), LHC searches (energy frontier), and leptogenesis (cosmic frontier). I will focus on some progress on the promising UV completions of $0\nu\beta\beta$ decay operators, which can be diagnosed with complementary searches at the HL-LHC and HE-LHC.

We explore a scenario of high scale supersymmetry where all supersymmetric particles except gauginos stay at a high energy scale $M_{\rm SUSY}$ which is much larger than the reheating temperature $T_\text{RH}$. The dark matter is dominated by bino component with mass around the electroweak scale and the observed relic abundance is mainly generated by the freeze-in process during the early...

We present the first analytic results of N3LO QCD corrections to the top-quark decay width. We focus on the dominant leading color contribution, which includes light-quark loops. At NNLO, this dominant contribution accounts for 95% of the total correction. By utilizing the optical theorem, the N3LO corrections are related to the imaginary parts of the four-loop self-energy Feynman diagrams,...

Electroweak dipole operators in the Standard Model Effective Field Theory (SMEFT) are important indirect probes of quantum effects of new physics beyond the Standard Model (SM), yet they remain poorly constrained by current experimental analyses for lack of interference with the SM amplitudes in constructing cross section observables. In this Letter, we point out that dipole operators flip...

Working to all orders in dimensionally-regularized QCD, we study the radiation of a photon whose energy is much lower than that of external partons, but much larger than the masses of some quarks. We argue that the conventional soft photon theorem receives corrections at leading power in the photon energy, associated with soft virtual loops of massless fermions. These additive corrections give...

The Higgs effective field theory (HEFT) is an effective field theory in the broken phase, providing a more general realization of the EW symmetry breaking, which includes the SMEFT as a particular case. There are more effective operators than the SMEFT and can be matched to the latter ones. I will discuss the HEFT, especially its effective operators basis. The key points are

• A general...

Ultra-light Dark Matter (ULDM) is one of the most promising DM candidates. Due to the Bose enhancement, we find the annihilation rate of the ULDM in the presence of background photon radiation can be greatly enhanced and produce a distinctive reflected electromagnetic wave with an angular frequency equal to the ULDM mass. We propose to utilize such stimulated annihilation to probe the ULDM...

The transverse spin effects can be measured at upcoming Electron-Ion Collider (EIC) and proposed Electron-Ion Collider at China (EicC) with polarized electrons or/and protons. The corresponding observables, single-spin asymmetry (SSA)/double-spin asymmetry (DSA), are suppressed in the Standard Model. We investigate the enhancement of DSA under new physical effects. We parameterize such...

Within the standard model, transverse single spin asymmetries in electron elastic scatterings can only arise from multi-photon exchanges. The A4@MAMI collaboration has measured the beam transverse single spin asymmetry in electron-proton elastic scattering from 315 to 1508 MeV (Phys. Rev. Lett. 124, 122003 (2020)). The data are significantly different from theoretical calculations based on...

Effective field theory (EFT) provides a model-independent framework for interpreting the results of dark matter (DM) direct detection experiments. In this study, we demonstrate that two fermionic DM-quark tensor operators ($(\bar{\chi} i\sigma^{\mu\nu} \gamma^5 \chi) (\bar{q} \sigma_{\mu\nu}q)$ and $(\bar{\chi} \sigma^{\mu\nu} \chi) (\bar{q} \sigma_{\mu\nu} q)$) can contribute to the DM...

In this talk, I will review the on-shell method of constructing the operator bases of effective field theories. The first task is to eliminate all the operator redundancies and obtain an independent basis, which is accomplished by adopting the Young Tensor method. Then a special basis of operators organized by representations of the symmetry groups, named J-basis, is introduced. Applications...

There is a significant interest in testing quantum entanglement and Bell inequality violation in high-energy experiments. Since the analyses in high-energy experiments are performed with events statistically averaged over phase space, the states used to determine observables depend on the choice of coordinates through an event-dependent basis and are thus not genuine quantum states, but rather...

We study the feeble sterile neutrino portal dark matter under the $Z_2$ or $Z_3$ symmetry. And summarizing the differences between $Z_2$ and $Z_3$ symmetry, which are mainly reflected in the generation, transformation, and various phenomenology.

Recently, the vector-like leptons (VLLs) as a simple extension to the standard model (SM) have attracted widespread attention both in theory and experiments. The present collider searches mainly focus on the studies of their prompt decays, which prefer a relatively large coupling. In this paper, we concentrate on searches for long-lived signatures of the singlet VLLs $F$ or their accompanying...

If the terrestrial environment is permeated by dark matter, the levitation experiences damping forces and fluctuations attributed to dark matter. This paper investigates levitodynamics with multiple stochastic forces, including thermal drag, photon recoil, feedback, etc., assuming that all of these forces adhere to the fluctuation-dissipation theorem. The ratio of total damping to the...

Quirk is a BSM particle carrying both the SM gauge charge and a new confining gauge charge. The produced quirk pair at the LHC can be long-lived and potentially be probed by several far detectors. We will talk about the probing prospect of FASER2, MATHUSLA, ANUBIS, SND@LHC, and FACET detectors to a few simplified quirk scenarios. A timing analysis at the FASER2 will be discussed in detail.

The exotic Z decays to a QCD-like dark sector provide unexplored opportunities at colliders. In this talk, we explore the region where the Z portal is generated via the mixing with a dark Z′. The phenomenological signatures of light Z’ are studied, with both dark shower signals in Z(Z') decays and exotic decays of B hadrons taken into account. The generated dark hadrons may serve as long-lived...

Recent advances in tabletop quantum sensor technology have enabled searches for nongravitational interactions of DM. Traditional axion dark matter experiments rely on sharp resonance, resulting in extensive scanning time to cover the wide mass range. In contrast, our study (named ChangE) introduces a novel method of actively tuning alkali and noble gas spins to the same Larmor frequency, where...

The small field inflation (SFI) of Coleman-Weinberg (CW) type suffers from precise tuning of the initial inflaton field value to be away from the true vacuum one. We propose a dynamical trapping mechanism to solve this problem: an ultra-supercooling caused by an almost scale-invariant CW potential traps the inflaton at the false vacuum, far away from the true vacuum dominantly created by the...

Supersymmetric models with nearly-degenerate light higgsinos provide a consistent solution to the naturalness problem under rigorous constraints from current experimental searches for sparticles. However, it is challenging to probe the compressed scenarios at collider experiments due to the hard-to-detect soft final states. To overcome this issue, strategies have been proposed to take...

We consider two Higgs doublet models (2HDMs) with both the Higgs potential and Yukawa interactions being aligned, which we call “double-aligned 2HDMs”. In this scenario, coupling constants of the discovered Higgs boson to the Standard Model (SM) particles are identical to those of the SM Higgs boson, and flavor changing neutral currents via neutral Higgs bosons do not appear at tree level. We...

The dynamics of quantum fields during cosmic inflation can be probed through their late-time boundary correlators. The analytic structure of these boundary correlators contains rich physical information about bulk dynamics and their relationship to cosmological collider observables. In this talk, I will focus on a distinctive nonanalytic behavior known as the nonlocal signal, which emerges at...

Phenomenological studies of cosmological collider physics in recent years have identified many 1-loop inflation correlators as leading channels for discovering heavy new particles around or above the inflation scale. However, complete analytical results for these massive 1-loop correlators are currently unavailable. In this work, we embark on a program of bootstrapping inflation correlators...

If the temperature of the hot thermal plasma in the Early Universe was within a few orders of magnitude of the quantum gravity scale, then the hoop conjecture predicts the formation of microscopic black holes from particle collisions in the plasma. These black holes may evaporate and produce the dark matter relic abundance observed today for a wide variety of dark matter masses. We study the...

We extend the framework of analyzing the 2HDM in its orbit space to study the one-loop effective potential before and after electroweak symmetry breaking in this work. We generalize the bilinear notation around the vacuum to study the global symmetries of the effective potential and present a geometric view of the scalar mass matrix and on-shell renomalization conditions.

We show that testing Bell inequalities in $W^\pm$ pair systems by measuring their angular correlation suffers from the ambiguity in kinetical reconstruction of the di-lepton decay mode. We further propose a new set of Bell observables based on the measurement of the linear polarization of the $W$ bosons, providing a realistic observable to test Bell inequalities in $W^\pm$ pair systems for...

We propose an alternative realization of Froggatt-Nielsen like mechanism in modular flavor models. The realization of mass and mixing hierarchies in the quark and charged lepton sectors can be realized, possibly without additional flavon field.

本次报告中我将会介绍宇宙相变引力波相关研究领域方面的进展，包括唯象学研究、相变动力学运动学及引力波计算、相变的新观测量如原初黑洞原初磁场，以及相变引力波的实验探测方面的进展。