Conveners
分会场三: 核子结构
- Xianglei Zhu (Tsinghua University)
分会场三: 强子物理
- Xu Sun (Institute of Modern Physics, Chinese Academy of Sciences)
分会场三: 高密核物质
- 伟杰 付 (大连理工大学)
分会场三: 高密核物质
- Jie Zhao (Fudan Unversity)
分会场三: 高密核物质
- 卫宁 张 (Harbin Institute of Technology)
分会场三: QCD与新物理
- Ben-Wei Zhang (Central China Normal University)
质子结构是物质结构研究和QCD整体研究的代表性方向。过去几十年间，在理论上建立了QCD improved parton model，对于高能标下质子反应给出了良好描述；在实验上利用各种DIS和Drell-Yan过程，整体测量了质子内各类夸克分布。然而，广泛使用的理论框架和经典实验测量手段并不能在质子内海夸克的产生机制、SU(2)/SU(3) flavor asymmetry、intrinsic heavy...
双轻子和光子等电磁探针对于揭示夸克物质电磁、热辐射和手征特性等具有不可替代的优势，一直是RHIC上重要的实验探索手段，近年来取得了良好的研究进展。2017年，STAR实验证实了超子整体极化的理论预言，自旋极化在夸克物质研究中的作用愈发重要。2021年，UPC中等效光子线性极化的理论预言得到实验证实，极化光子作为新的电磁探针，其作用得到不断丰富。
本报告将以电磁探针的实验测量作为线索，总结RHIC上的电磁探针物理研究进展，包括通过双轻子和直生光子研究QGP特性、通过极化光子探索强磁场下基本物理过程和原子核结构等。同时，报告将讨论相关实验研究的未来机遇。
Sparked by measurements of the transverse polarization of $\Lambda$ by Belle, much efforts are devoted to the study of the polarized $\Lambda$ TMD fragmentation function (TMDFF) $D_{1T,q}^{\perp\Lambda}$. Several questions, such as the isospin symmetry and gluonic contributions, remain unsolved due to limited range of experimental data. Inspired by the upcoming measurements of $\Lambda$...
关联函数和散射振幅包含微观相互作用的核心物理信息，是量子场论中连接理论框架和实验数据的桥梁。在微扰量子场论中，关联函数和散射振幅的标准计算方法是按照耦合常数微扰展开，进而逐阶计算费曼图。在圈图层次上的所有费曼图中，单圈费曼图通常对应着次领头阶的贡献，不仅具有不可或缺的重要性，而且为进一步研究多圈费曼图的微扰贡献提供必要的准备。计算单圈费曼积分的传统方式是，把表观上不同的单圈费曼积分作为彼此无关的对象，进行“逐一的”（one-by-one）计算。采取这种one-by-one方式计算单圈费曼积分，具有“（数量）少、（速度）慢、（质量）差、（成本）费”的缺点。Passarino-Veltman...
Conventionally, quarks are believed to carry a baryon number of B = 1/3. Therefore, three quarks combine to form a baryon with B = 1, while a quark-antiquark pair form a meson with B = 0. Meanwhile, an alternative picture was proposed in early 1970s, which stipulates that valence quarks are connected by gluons in a Y-shaped topological structure, called the baryon (or gluon) junction. It is...
The viscous properties of quark-gluon plasma (QGP) are closely related to the evolution of high-energy heavy-ion collisions and the momentum distributions of final-state hadrons. With the progress of the RHIC beam energy scan experiments, an important question is how transport coefficients (such as shear viscosity and bulk viscosity) evolve dynamically in QGP under different collision...
During the chiral phase transition, the pion string is predicted to be produced both in the heavy ion collisions and early universe according to the phenomenology of QCD theory. In this talk, we will present our recent studies on the topic of the production rate of the pion string in a hot and dense quark matter. For a second-order phase transition in hot but low density region, We apply the...
量子色动力学（QCD）相图结构的研究是核物理研究领域的热点与前沿，寻找QCD相变信号和确定QCD相图结构对于高能物理、宇宙学以及核天体物理等领域具有非常重要的意义。该工作主要是基于电荷守恒版多相输运（AMPT）模型对守恒荷涨落性质进行了研究，为未来在相对论重离子碰撞实验中探索QCD相结构提供一些理论参考。考虑到AMPT模型遵循电荷守恒定律对研究守恒荷涨落的重要性，故修正了ART模型中电荷不守恒的一些强子反应道等问题。
基于电荷守恒版AMPT模型计算了$\sqrt{s_{NN}}=7.7$...
The ALICE collaboration has recently reported the first measurements of the skewness and kurtosis of mean transverse momentum fluctuations in Pb–Pb collisions at 5.02 TeV, Xe–Xe collisions at 5.44 TeV, and pp collisions at 5.02 TeV. A positive skewness is observed and attributed to the hydrodynamic evolution of the quark-gluon plasma (QGP) formed in heavy-ion collisions. In this study, we...
Two-particle correlation analysis serves as a powerful tool for probing the space-time evolution and dynamical properties of particle-emitting sources produced in relativistic heavy-ion collisions. The experimentally extracted source radii reflect the system's spatial extent at kinetic freeze-out, the final stage where particles stop interacting. Compared to pions, kaons offer enhanced...
Due to the hot dense environment, quark matter is probably emerge in compact stars, e.g. the cold neutron stars, the hot proto-neutron stars or the remnant of two neutron star merger. At present, it is quite important to look for possible observational signals to distinguish the hybrid stars from normal neutron stars. Concern the recent development in gravitational wave observation, we...
Because of their weak interactions with the strongly interacting matter produced in relativistic heavy-ion collisions, dileptons provide an ideal probe of the early dynamics of these collisions. Here, we study dilepton production using a partonic transport model that is based on an extended Nambu-Jona-Lasinio (NJL) model. In this model, the in-medium quark masses decrease with increasing...
In heavy-ion collisions, directed flow ($v_1$) and elliptic flow ($v_2$) represent the first and second harmonic coefficients in the Fourier expansion of the final-state particle azimuthal distribution. These coefficients are sensitive to the equation of state (EoS) and the degrees of freedom in the produced medium. Measuring $v_1$ and $v_2$ of identified particles provides a powerful tool for...
The electromagnetic probe offers a distinctive approach to exploring baryon structure. Within the baryon octet, only protons and neutrons can be directly studied through scattering experiments, while the remaining baryons require investigation via positron-electron annihilation experiments, which are constrained by their lifetimes. Utilizing collision data with an integrated luminosity of...
Spin polarization, as a novel method for detecting the rotational properties of QGP which are produced in relativistic heavy-ion collisions, has attractd great interest. We study the impact of parton spin polarization on the effective transport and thermodynamic coefficients and the QCD critical point in non central light- and heavy-ion collisions. By employing the novel kinetic theory...
Event-by-event mean transverse momentum fluctuations ($p_\mathrm{T}$) serve as a sensitive probe of initial state overlap geometry and energy density fluctuations in relativistic heavy-ion collisions. We present a systematic investigation of $p_\mathrm{T}$ fluctuations in Au+Au collisions at $\mathrm{\sqrt{s_{NN}}}$ = 3.0–19.6 GeV, examining their centrality and energy dependence with the...
