中国物理学会高能物理分会第十一届全国会员代表大会暨学术年会

散射截面是研究粒子基本结构和相互作用的基本观测量。当散射过程涉及多个能标时，精确计算结果很难得到。当能标之比很大时，结果会展示出大对数结构。在领头幂次阶，该大对数已经了解的比较清楚了。但是在次领头幂次阶，会出现新的困难，例如端点发散。这时需要发展新的理论来处理这些困难。我将介绍这方面的最新进展。

We investigate the extent to which perturbative calculations of the electroweak phase transition are arbitrary and uncertain, owing to their gauge, renormalization scale and scheme dependence, as well as treatments of the Goldstone catastrophe and daisy diagrams. Using the complete parameter space of the Standard Model extended by a real scalar singlet with a Z2 symmetry as a test, we explore the properties of the electroweak phase transition in general Rxi and covariant gauges, OS and MSbar renormalization schemes, and common treatments of the Goldstone catastrophe and daisy diagrams. Reassuringly, we find that different renormalization schemes and different treatments of the Goldstone catastrophe and daisy diagrams typically lead to only small changes in predictions for the critical temperature and strength of the phase transition. On the other hand, the gauge and renormalization scale dependence may be significant, and often impact the existence of the phase transition altogether.

我们将报告LHCb实验在奇特强子态产生测量方面的结果。

Double J/psi at CMS

Double J/psi at ATLAS

A near-threshold peaking structure, dubbed X(3960), is observed in the Ds+Ds- mass spectrum with significance greater than 12 standard deviations, using proton-proton collision data collected with the LHCb detector at centre-of-mass energies of 7, 8 and 13 TeV. Its quantum numbers is measured to be J^{PC}=0^{++} with the amplitude analysis. It may be a candidate with the quark content: c cbar s sbar candidate.

The first discovery of pentaquarks at LHCb in 2015, opens new window to study QCD. The LHCb experiment has the large dataset and excellent detector performance in such searches. In this talk, the latest results on pentaquark study in B-meson decays from LHCb will be discussed.

We calculate the s-wave scattering length in the $0^+$ sector of $\eta_c\eta_c$ and the $2^+$ sector of $J/\psi J/\psi$ using three $N_f=2$ twisted mass gauge ensembles
with the lattice spacing $a=0.0667,0.085,0.098$ fm, respectively.
The scattering lengths are extracted using the conventional L{\"u}scher finite size method. We observe significant discretization effects and therefore perform a continuum extrapolation. Finally, we obtain the results as $a^{0^+}_{\eta_c\eta_c}=-0.104(09)$ fm and $a^{2^+}_{J/\psi J/\psi}=-0.165(16)$ fm, where the errors are statistical errors with the uncertainties of lattice spacing taken into account. Both scattering lengths are negative, indicating that the interaction between the two charmonia are repulsive in nature in both channels being studied.

Two-particle correlations with $V^{0}$ $(K^{0}_{S}, \Lambda/\bar\Lambda)$ and charged hadrons as trigger particles of transverse momentum
$8 < p_\mathrm{T,trig}< 16$ GeV/c, and associated charged particles of $1 < p_\mathrm{T,assoc}< 8$ GeV/c, are studied at mid-rapidity in pp and most central Pb-Pb collisions at $\sqrt{s_\mathrm{NN}}$ = 5.02 TeV with the ALICE detector at the LHC.
After contributions of the flow background is subtracted, the per-trigger yields are extracted, and the nuclear modification factor, $I_\mathrm{AA}$, is calculated on both near and away side.
The results of $I_\mathrm{AA}$ show strongly suppression on away-side and enhancement at low $p_\mathrm{T}$ on both near- and away-side consistence with previous ALICE measurement of neutral pion ($\pi^{0}$-h) and charged hadrons (h-h) in Pb-Pb collisions at $\sqrt{s_\mathrm{NN}}$ = 2.76 TeV. In addition, the data are described within uncertainties by AMPT and HIJING event generators.

This talk will present the R&D; study of the prospect and feasibility to deploy the fixed-target experiment utilizing the high rate single electron beam from the SHINE facility under construction. The project is officially sponsored by NSFC Original Exploration Project 2021 and Shanghai pilot program for basic research.

To resolve the long-standing discrepancy between the precision measurement of bottom quark forward-backward asymmetry at LEP/SLC and the Standard Model prediction, 
we propose four different novel methods to probe the $Zbb$ couplings by measuring $gg\to Zh$ production, Z boson exclusive decay at the LHC and (average jet charge weighted) single-spin asymmetry at the HERA and EIC. We demonstrate that $gg\to Zh$ cross section, the branching ratio of $Z\to \Upsilon(ns)+\gamma$, 
and jet charge weighted single-spin asymmetry are sensitive to the axial-vector component of the $Zbb$ coupling, while the single-spin asymmetry is sensitive to the vector component. The apparent degeneracy of the $Zbb$ couplings implied by the LEP precision electroweak measurements could be resolved by the current 13 TeV LHC $Zh$ data. 
We also show the potential to verify or exclude the LEP data and resolve the AFB puzzle through those methods.

As one of those long-standing experimental anomalies from the LEP era, albeit mild, the discrepancy to the standard model prediction in the $Zb\bar b$ coupling keeps drawing attention over the years as the LHC accumulates data. So far, differential data and studies from electroweak production of the bb pair and other potentially sensitive channels at the LHC and LHCb are yet to become competitive with the existing $Z$-pole measure from LEP. We propose in this study to look at another LHC signal, the $b\bar b +Z/\gamma (\to \ell\ell)$ associated production, both on and off-Z-mass-shell region. The varying dependence on the concerned couplings through interplay of Z and photon interference pattern in the $b\bar b\ell\ell$ final states offer distinct constraint power.

The ForwArd Search ExpeRiment (FASER), is a recently proposed experiment at the LHC that can detect light, long-lived particles. In this work we study the prospect of detecting light CP-even and CP-odd scalars at the FASER. We develop the general formalism for the scalar production and decay from mesons at LHC, given modified couplings of the scalars to the SM particles, as well as summarizing the relevant GeV-scale experiment constraints. We then analyze the light scalars in the large $\tan\beta$ region of the Type-I 2HDM, in which a light scalar with relatively long life time could be accommodated.

The three generations of leptons and quarkons have been discovered. The left-right asymmetry in the weak interaction of leptons and quarks has been confirmed. Astronomical observations have showed that the number of baryons and antibaryons is asymmetrical in the observabale cosmos. This paper shows that there is the same origin of the left-right asymmetry and the asymmetry of number of baryons and antibaryons. The three generations of leptons and quarkons and the two sorts of asymmetry are explained in this paper based on the SU(5) grand unified model with hadrons as nontopological solitons.

We investigate the $T_{cc}^{+}$ as a $DD^{*}$ molecule with $J^{P}=1^{+}$ in the framework of the one-boson-exchange potential model. The isospin breaking effect and $S-D$ wave coupling are taken into account carefully. We adopt the complex scaling method to study the $DD^{*}$ system and obtain a quasibound state corresponding to the $T_{cc}^{+}$.

Summary: The binding energy of $DD^*$ system relative to the $D^{0}D^{*+}$ and width are $-354$ keV and $61$ keV respectively. The isospin breaking effect is found to be enormous, and the $S-$wave $D^{0}D^{*+}$ and $D^{+}D^{*0}$ components give dominant contributions with the probabilities of $72.1\%$ and $27.1\%$ respectively. In addition, we do not find any resonances in the $DD^{*}$ system. As a by-product, we study the $X(3872)$ as a $(D\bar{D}^*-D^*\bar{D})/\sqrt{2}$ molecule with $J^{PC}=1^{++}$. We also find a quasibound state corresponding to the $X(3872)$. Its binding energy relative to the $D^{0}\bar{D}^{*0}$ threshold and width are $-111$ keV and $26$ keV respectively. The $S-$wave $(D^{0}\bar{D}^{*0}-D^{*0}\bar{D}^{0})/\sqrt{2}$ component dominates this state with the probability of $92.7\%$.

AMS自2011年开始在国际空间站上运行，迄今已在暗物质和反物质寻找、宇宙线研究取得重大成果，发现了许多不能被现有理论解释的新现象。美国白宫已于2021年12月31日宣布国际空间站将运行到2030年，并计划运行AMS直到国际空间站使命结束。为进一步提高AMS科学产出，理解已发现的新现象，特别是宇宙线正电子、反质子和高电荷原子核能谱的精确测量，更好地发挥在反物质等探索研究方面独到的优势，AMS实验计划于近期开始进行探测器升级，安装由两层共8平方米的硅微条探测器组成的Layer0硅径迹室。
中科院高能所将负责完成L0 硅径迹室的全部硅探测器的研制，并参加其总体集成和空间环境模拟试验。AMS实验的其它国际合作者将负责读出电子学、机械结构、冷却、供电、空间验证和安装等，NASA已基本同意中国科学家以这种方式参加升级项目。探测器整体精度要求10微米，是一项前所未有的挑战。本文将向大会介绍AMS L0 硅径迹室升级的建造方案，并汇报进展情况。
本次升级对中国科学家而言，既可以掌握先进的硅探测器技术，也可以了解相关空间技术及质量控制，对中国下一代的空间科学项目，如中国空间站上的HERD实验具有十分重要的意义。

This poster will present a measurement of the charge conjugation and parity ($CP$) properties in the Higgs boson interaction with $\tau$ leptons. The Yukawa interaction is generalized with a single mixing angle parameter $\phi_{\tau}$ to describe $CP$-odd interactions between the Higgs boson and $\tau$ leptons. The study is based on a measurement of $CP$-sensitive angular observables defined by the visible decay products of $\tau$ lepton decays, performed using a data sample corresponding to 139 fb$^{-1}$ of proton–proton collisions recorded at a center-of-mass energy of $\sqrt{s}$= 13 TeV with the ATLAS detector at the Large Hadron Collider.
Without assuming Standard Model hypothesis for the $H\rightarrow\tau\tau$ signal strength,
the mixing angle $\phi_{\tau}$ is measured to be $9 \pm 16^{\circ}$, with an expected value of $0 \pm 28^{\circ}$ at the 68\% confidence level.
The pure $CP$-odd hypothesis is disfavoured at 3.4 standard deviations.
The results are compatible with the predictions for the Higgs boson in the Standard Model as well as $CP$-violating scenarios.

In the SM effective field theory (SMEFT), the gauge interactions can be extended by dimension-8 operators contributing to anomalous triple gauge couplings (aTGCs) and anomalous quartic gauge couplings (aQGCs). The VBS processes at hadron colliders and the tri-boson production at lepton-colliders are suitable for probing aQGCs, and the di-boson production at lepton-colliders is suitable for studying nTGCs. We discuss the event selection strategies for measuring aQGCs or nTGCs, and give constraints on the anomalous gauge couplings. The validity of SMEFT has been taken into account in our works.

格点模拟为计算早期宇宙对称性破缺过程及其可能产生的随机引力波功率谱提供了可能，这为引力波探测实验提供了重要的随机引力波源，引力波探测实验可以和对撞机实验互补的来区分早期宇宙对称性破缺的模式及其背后的新物理。我将在此报告中和大家分享我们利用格点规范场论模拟早期宇宙对称性破缺过程所取得的一些进展，包括：强一阶电弱相变和宇宙弦形成等的研究。

BESIII has collected 2.93 and 6.32 fb^-1 of e+e- collision data samples at 3.773 and 4.178-4.226 GeV, respectively. We will report precision measurements of fDs, |Vcs| and test of lepton flavor universality by studying the leptonic decays of Ds -> l+nu with tau+ -> rho+nu, pi+nu, and e+nunu. We will also report the studies of Ds -> pi0pi0e+nu and KSKSe+nu, inclusive Ds semileptonic decay, updates of D-> Ke nu with a new method.

BESIII has collected 2.93 and 6.32 fb^-1 of e+e- collision data samples at 3.773 and 4.178-4.226 GeV, respectively. We will report the observation of a new a0 resonance and amplitude analyses of Ds -> KSK+pi0, KSKSpi+, pi+pi0eta', KK3pi, Kpipipi0, and pi+pi0pi0. We will also report the transverse polarization determination in D0 -> omega phi, the KS/KL asymmetry studies in D0 -> KLX (X=eta, eta', omega and phi), observation of the new decay mode D^*0 to D^0 e^+e^-, and the measurements of the branching fractions of some D0(+) CF and DCS decays will also presented. In addition, BESIII has collected 4.5 fb^-1 of e+e- collision data between 4.6000 and 4.6999 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+ -> npi+.

We will report selected recent results of new physics searches at LHCb via the study of b-hadrons decays that are rare or forbidden in the standard model of particle physics.

BESIII has collected 2.5 B $\psi(2S)$ events and 10 B $J/\psi$ events. The huge data sample provide an excellent chance to search for new physics in charmonium decays. We report the search for the decay $J/\psi\to\gamma + invisible$ and a potential light Higgs A0 in radiative J/psi decay. We also search for the J/psi rare weak decay to $D^-e^+\nu_e +c.c.$, and present the most stringent constraints of $10^{-6}$ at 90\% confidence level. The huge J/psi data set also produce lots of hyperon events at BESIII, which allow us to search for the rare decay of hyperon, such as the invisible decay of Lambda, \Xi semi-leptonic decay. The FCNC process for D0->pi0 vv is also search with the near threshold D0 events at BESIII.

We accomplish the analytical computation of the pure weak annihilation non-leptonic $B$-meson decay amplitudes at leading power in the heavy quark expansion. The novel observation regarding such fundamental hadronic quantities is that adding the missing hard-collinear contribution on top of the hard gluon exchange effect eliminates rapidity divergences entering the convolution integrals of factorization formulae.
Subsequently we identify the perturbative enhancement mechanism due to the penguin contractions of the current-current operators from the weak effective Hamiltonian,
which yields the significant impacts on the CP violating observables.

We compute for the first time the long-distance penguin contribution to the double radiative $B$-meson decays
due to the purely hadronic operators acting with the electromagnetic current in the background soft-gluon field
from first field-theoretical principles by introducing a novel subleading $B$-meson distribution amplitude.
The numerically dominant penguin amplitude arises from the soft-gluon radiation off the light up-quark loop rather than the counterpart charm-loop effect on account of the peculiar analytical behaviour of the short-distance hard-collinear function. Importantly the long-distance up-quark penguin contribution brings about the substantial cancellation of the known factorizable power correction possessing the same multiplication CKM parameters, thus enabling $B_{d, \, s} \to \gamma \gamma$ to become new benchmark probes of physics beyond the Standard Model.

在文章arXiv:2112.14215（李新强，沈萌，王东洋，杨亚东，袁兴博）和arXiv:2205.02205（李新强，谢泽俊，杨亚东，袁兴博）中，我们分别研究了用具有顶夸克味改变和味守恒中性流的$Z^\prime$模型来解释$b\to s \ell^+ \ell^-$反常。在后一工作中，我们还考虑了额外解释最近CDF观测到的W玻色子质量的可能性。