Conveners
分会2：强子物理与味物理
- Chair1：何吉波 (UCAS)
- Chair2：梁剑 (华南师范大学)
分会2：强子物理与味物理
- Chair1：张艳席 (北京大学)
- Chair2：吴兴刚 (Chongqing University)
分会2：强子物理与味物理
- Chair2：陈伟 (Sun Yat-Sen University)
- Chair1：孙鹏 (IMP)
分会2：强子物理与味物理
- Chair2：刘晓海 (Tianjin University)
- Chair1：王雄飞 (Lanzhou University)
位于欧洲核子研究中心（CERN）的 LHCb 实验通过对底强子和粲强子的精确测量，针对CP破坏和强子谱学等前沿课题进行研究，理解标准模型、探索新物理。本报告将概述LHCb前沿课题，重点介绍 LHCb 实验在重味强子CP破坏及谱学等研究领域的前沿进展。
This talk is an overview of recent Belle II results on measuring the CKM matrix elements, LFU, CPV, and hadron spectroscopy.
The BESIII experiment has collected 20.3 fb-1 and 7.33 fb-1 of e+e- collision data at center-of-mass energies of 3.773 GeV and 4.128-4.226 GeV, respectively. This presentation will provide an overview of recent studies using (semi)-leptonic D decays at BESIII. We will present the first experimental investigation of Ds*+ to l+ nu decays, along with improved measurements of the CKM matrix...
The BESIII experiment has collected 10 billion J/ψ events and 2.7 billion ψ(3686) events. The huge charmonium data samples allow us to search for rare decay processes allowed in the standard model and new physics beyond the standard model. In this talk, we report the search for charged lepton flavor violation process ψ(3686)→eμ, charmonium weak decay processes J/ψ→γD0, J/ψ→D0μ+μ-, J/ψ→D0K0*,...
核子自旋结构是理解强相互作用非微扰动力学的重要问题之一。本报告将介绍我们利用格点 QCD对核子部分子分布函数及其自旋相关物理量的第一性原理研究。首先，我们在大动量有效理论框架下计算核子的非极化和螺旋度 PDF，并重点讨论极化比值 $\Delta q/q$ 以及纵向自旋不对称性 $A_1^p$、$A_1^n$。这些比值能够直接刻画不同味道夸克在给定动量分数下与核子自旋同向或反向的程度，是连接格点 QCD、整体拟合和极化深度非弹散射实验的重要物理量。其次，我将介绍我们对夸克TMDPDFs的计算，包括非极化分布、Boer-Mulders 函数、螺旋度分布和 worm-gear 分布等。这些结果为从一维动量结构到三维横动量依赖结构理解核子自旋提供了新的第一性原理信息，并为未来 JLab 和 EIC 等极化实验提供第一性原理的理论参考。
Fragmentation Function (FF) plays a crucial role in describing the hadronization process. We report the measurements of normalized differential cross sections of inclusive pi0 and Ks production as a function of hadron momentum at six energy points with q^2 transfer from 5 to 13 GeV^2 at BESIII. The results with a relative hadron energy coverage from 0.1 to 0.9 significantly deviate from...
Three structures, denoted as X(6600), X(6900), and X(7100), have been observed in the J/\psi J/\psi mass spectrum and are interpreted as candidates for a family of fully-charm tetraquark states. Using proton-proton collision data collected by the CMS detector corresponding to an integrated luminosity of 315 fb(^{-1}), the J/\psi J/\psi spectrum is studied with substantially improved...
The dominance of matter over antimatter in the universe has consistently driven the pursuit of new physics beyond the Standard Model that violates charge-parity (CP) symmetry. The BESIII experiment has collected 10 billion J/ψ events and 2.7 billion ψ(3686) events. With the quantum entangled decays of J/ψ, we can search for the new source of CP violation and precisely measure the electric...
我将报告LHCb上双重味重子实验研究近期进展，包括单电荷双粲重子的首次发现，这是利用升级后的LHCb探测器发现的首个新粒子。
In this talk, we will present our recent results on the $J/\psi$ and exotic hadron productions in high energy nuclear collisions using the parton and hadron cascade model PACIAE. For the $J/\psi$ sector, we will provide a quantitative analysis of the relative contributions for different production mechanisms and their energy and rapidity dependence in the inclusive $J/\psi$ production. We will...
Using the form factors of the transtions $B\to T$ with $T$ refering to a tensor meson, such as $a_2(1320), f_2(1270),K^*_2(1430), D_2^*(2460)$ and $D^*_{2s}(2573)$, within the covariant light-front quark model (CLFQM), we
provide a detailed investigation of the corresponding semi-leptonic decays $B\to T\ell\nu_\ell$ with $\ell=e,\nu,\tau$. All the branching ratios of these
decays are larger...
Tau 物理是Belle II实验上的重要研究课题之一。Belle II目前已经采集了842 pb-1数据，并正在产出越来越多的tau物理研究成果。本报告题目是 “tau physics at Belle II”, 将报告Belle II实验最新的tau物理研究进展，包括通过 tau->pi Ks nv寻找CP破坏，一系列tau衰变中寻找轻子味破坏，tau轻子寿命的测量等课题。
Light-cone distribution amplitudes (LCDAs) are fundamental nonperturbative objects governing hard exclusive processes and heavy-flavor decays. Over the past decades, lattice QCD studies of LCDAs have evolved from traditional calculations of low-order moments to the recent development of approaches based on large-momentum effective theory (LaMET), which enable direct access to the Bjorken-x...
Light-cone distribution amplitudes (LCDAs) frequently arise in factorization theorems involving light and heavy mesons. We will talk about the power corrections in the extraction of the B-meson LCDAs.
BESIII has collected 20.3 and 7.33 fb^-1 of e+e- collision data samples at 3.773 and 4.128-4.226 GeV. These constitute the world's largest samples of D anti-D and Ds anti-Ds pairs, respectively, providing a unique laboratory to probe the non-perturbative dynamics of Quantum Chromodynamics (QCD) in the charm sector. We will present the measurement of branching fractions of fifteen Ds+ hadronic...
The world’s largest sample of J/ψ events accumulated at the BESIII detector offers a unique opportunity to investigate η and η′ physics via two body J/ψ radiative or hadronic decays. In recent years the BESIII experiment has made significant progresses in η/η′ decays. A selection of recent highlights in light meson decays at BESIII are reviewed in this report, including the precision...
Short-range correlation pairs (SRCs)---core of nuclear structure, composed of highly off-shell nucleons---are mostly studied via electron-nucleon scattering, leaving a gap in meson-based probes. We propose probing SRC off-shell nucleons via quasielastic $\pi^+$-bound proton scattering ($\pi^+ p \to \pi^+ p$) at electron-positron colliders, of which the beryllium-based ($^{9}$Be) beam pipe of...
在本报告中，针对具有C宇称的三体强子系统，我们预言了一个良好的三体强子分子态候选者。该态不与传统的两体强子分子态及QCD裸态混合，我们进一步介绍了其质量、衰变性质和产生过程，并探讨了其在未来实验中是否可被观测到。此外，我们发现在该系统中存在一种与C宇称相关的相互作用，表现为三体力。通过系统分析该系统的质量与均方根半径，以及哈密顿量平均值，我们确认了一个研究三体力的理想体系。
Based on the large data samples of 10 billion J/ψ and 2.7 billion ψ(3686) events collected with the BESIII detector, recent progress in hyperon spectroscopy, including the observations of Ξ(1720) and Σ(2330), will be presented. In addition, new radiative decay modes of Λ(1520) and Λ(1670) will be reported. Prospects for hyperon spectroscopy and decay studies at BESIII will also be discussed.
低质量粲偶素自旋单态eta_c和h_c粒子是研究粲偶素衰变动力学、检验强相互作用相关模型的重要实验平台。利用BESIII实验采集的27亿psi3686和100亿J/psi事例，本报告将介绍近期关于自旋单态粒子产生和衰变研究的进展，包括首次测量eta_c -> gamma gamma衰变的绝对分支比、对Jpsi-> gamma eta_c电磁跃迁衰变分支比的精度测量，首次观测到若干eta_c衰变模式，以及发现h_c的辐射衰变gamma f_2(1270)等。这些结果为理解非微扰QCD效应提供了新的实验信息。
In this talk, we review the recent result from ATLAS on the all-charm tetraquark search. It covers both the di-J/psi and J/psi+psi(4S) final states. Fitted resonance parameters from different fit models are compared. The ratio of branching fractions of X(6900) decaying into these two states is also provided. These results shed light on the nature of the all-charm tetraquarks.
BESIII has accumulated 4.5 fb^-1 of e+e- collision data within the 4.6 and 4.7 GeV energy range, which provide the largest dataset of Lambda_c- Lambda_c pairs in the world. We will present a novel way for exploring CP violation using the Lambda_c- Lambda_c threshold data and the first observation of the transverse polarization of Lambda_c+ in the reaction e+e--> Lambda_c+ Lambda_cbar-....
BESIII实验在质心能量位于3.7 GeV到4.95 GeV之间的近50个能量点采集了积分亮度约50 fb-1的精细扫描数据，对多个遍举反应过程的产生截面进行了精确测量，包括开粲末态、隐粲末态以及轻强子末态。通过对反应截面线型的研究，在重子末态中发现psi3770显著的信号；在高质量能区也发现多个反应过程的截面在4.5 GeV、4.6 GeV和4.75 GeV附近有增长。该报告将总结近期BESIII实验在矢量粲偶素和类粲偶素研究方面的最新进展，这些精确的测量将为理解矢量粒子的性质提供重要实验输入。
Belle II实验是设计亮度最高的正负电子对撞超级B介子工厂。运行至今，Belle II实验对撞亮度超过0.5x10^35cm-2s-1的水平，采集的B介子数据样本超过Belle实验。Belle II实验正在开展味物理与CP破坏，强子物理与奇特强子态，新物理等领域的广泛研究。报告将介绍Belle II实验的进展，以及实验升级计划。
Using （2259.3 +/-11.1） ×106 ψ（2S） events acquired with the BESIII detector, the branching fraction ofψ（2S） → ττ is measured with improved precision to be（3.240+/- 0.023 +/-0.081） × 10−3, where the first and second uncertainties are statistical and systematic, respectively, which is consistent with the world average value within 1 standard deviation. This value, along with those for the...
重味强子单举半轻衰变是检验标准模型和研究重夸克动力学的重要过程。已有电子末态的粲介子单举衰变研究可以用于提取 HQET 非微扰参数，为进一步研究缪子末态提供了理论基础。
本报告将介绍我们对粲介子缪子末态半轻单举衰变的研究。在标准模型框架下，我们保留有限轻子质量效应，计算相关衰变宽度，并给出缪子末态与电子末态比值的标准模型预言。这类比值中许多共同理论不确定性可以相互抵消，因此是检验轻子味普适性的较干净观测量。
最后，我将简要讨论该结果对 BESIII 和未来超级 tau-charm 工厂相关测量的意义，以及后续引入更高量纲算符贡献的理论改进方向。
We present a comprehensive next-to-leading order (NLO) QCD sum rule analysis
for light hybrid mesons with JPC = 1−−, incorporating condensates up to dimension-8 and NLO corrections to the perturbative, gluon condensate, and four-quark condensate contributions. These corrections are found to be substantial and reveal the necessity of contributions beyond leading order. Employing both Laplace...
底强子衰变中的轻子普适性检验是寻找超出粒子物理标准模型的新物理的灵敏探针，也是目前粒子物理实验前沿热点课题。在这个报告中，我们将报告LHCb上关于Bc介子半轻衰变中的轻子普适性检验即R(J/psi)的最新结果。
Following the most precise charm lifetime measurements as the first charm wave, which benefited from improved detector performance, the Belle II experiment has recently obtained a new set of charm physics results based on half of the current Belle II integrated luminosity. I will present these results, covering searches for CP violation in charm particles, hadronic decays of charmed baryons,...
This talk presents new perspectives on precision nucleon tomography using high-order QCD calculations and jet substructure. I will discuss the winner-take-all axis for extending qT subtraction to jet processes, enabling NNNLO predictions for SIDIS. Novel observables such as one-point energy correlators access the nucleon transversity distribution. Furthermore, we explore quantum decoherence in...
We propose a probe of the TMD and spin asymmetry in back-to-back deep-inelastic scattering using only the signs and directions of charged tracks, with no calorimetric or particle-identification information required.
强相互作用与电磁相互作用是自然界两种基本相互作用，也是粲偶素衰变中最重要的两类贡献。基于SU(3)理论并结合实验分支比的间接计算表明，J/ψ衰变中的强-电磁相对相位普遍接近90°，而其他粲偶素（如ψ(2S)、ψ(3770)）则呈现出其他可能的取值。目前，该相角是否具有普适性在理论上仍是一个悬而未决的问题，其取值对于理解“ρπ疑难”、“ψ(3770)-nonDDbar衰变”，以及粲偶素各类强子衰变分支比的测量均具有直接输入意义。BESIII实验利用扫描截面方法，对J/ψ、ψ(2S)及ψ(3770)能区若干强子末态的产生截面谱进行了测量，并从中直接提取了该相角。本报告将基于BESIII的扫描实验结果，对该相角问题进行讨论。
标准模型虽然取得了巨大成果，但仍未能回答反物质去哪了，暗物质是什么等重大科学问题，因此寻找新物理是目前粒子物理实验最重要的目标之一。稀有衰变是精确检验标准模型和间接寻找新物理的重要途径。LHCb实验利用海量质子-质子对撞数据能精确研究重味强子的稀有衰变，主要包括味道改变带电流过程、味道改变中性流过程和轻子普适性检验等间接寻找新物理信号，与直接寻找有效互补。
We investigate the $\pi^0\eta$ photoproduction off protons using a 4π electromagnetic calorimeter BGOegg at Spring-8 BL31LEP with a linearly polarized photon beam produced via laser Compton scattering in the energy region of 1.3−2.4 GeV. The conventional beam asymmetry $\Sigma$ is obtained with the quasi-two-body approach, while $I^c$ and $I^s$ are deduced via exploiting the full three-body...
为什么不同夸克的味量子数（包括同位旋I及其投影I3以及S，C，B∗ ，T，共6个）不同而且繁琐？为什么味量子数在弱相互作用下不守恒？为什么超荷Y是一个重子数和部分味量子数的混合量，在盖尔曼-西岛公式却与I3并列？等等。从对这些问题的思考出发，提出了费米子量子数F。F是费米子（包括夸克和轻子）的味相关相加性量子数，在弱、电磁、强相互作用下都守恒，并且关系式 Q/e=(F0+F)/2（F0为单位电弱荷，包含了重子数和轻子数）适用于所有费米子，比盖尔曼-西岛公式（只用于夸克）更具普遍性。弱相互作用选择定则之前只是经验的，现在能用F守恒推导出来,...
