Conveners
S3：中高能核物理
- Defu Hou (CCNU)
- Huan Zhong Huang (Fudan University)
S3：中高能核物理
- Yifei Zhang (University of Science and Technology of China)
- Qinghua Xu (Shandong University)
S3：中高能核物理
- 汉中 张 (Central China Normal University)
- Xin-Nian Wang (Central China Normal University)
S3：中高能核物理
- Qun Wang (University of Science and Technology of China)
- Xu-Guang Huang (Fudan University)
S3：中高能核物理
- Zhongbao Yin (华中师范大学)
- 笙琴 冯 (三峡大学理学院)
S3：中高能核物理
- Guo-Liang Ma (Fudan University)
- Yaxian Mao (Central China Normal University)
Yi Yin
(IMP)
10/10/2019, 08:30
中高能核物理
相变临界点是描述相结构最重要的特征量。QCD相图是否存在从一级相变到连续相变的临界点，是高能核物理方向还没有得到解答的重大问题之一。包括中国在内的世界科学强国都在进行或者计划进行重离子对撞来解答这个问题。此前，研究者通常用QCD物质的静态特诊去预言临界信号，但是在重离子对撞的环境下，临界信号最终将是由动力学特性所决定。 在这个报告中，我将综述这一前沿方向的新进展，并展望未来用于探索中高重子密度区的大型科学装置，如中国的HIRFL（Heavy Ion Research Facility in Lanzhou），将出现的新的物理发现的机遇。
Prof.
Heng-Tong Ding
(Central China Normal University)
10/10/2019, 08:55
中高能核物理
We will firstly present a lattice QCD based determination of the chiral crossover transition temperature at zero and nonzero baryon density[1]. We obtained a precise result for $T_{pc}=156.5\pm1.5$ MeV at zero baryon density. For analogous thermal conditions at the chemical
freeze-out of relativistic heavy-ion collisions, we found
$\kappa^B_2$=0.012(4) and $\kappa^B_4$=0.000(4). We will...
Dr
Jun Xu
(Shanghai Institute of Applied Physics, CAS)
10/10/2019, 09:15
中高能核物理
多相输运模型是描述相对论重离子碰撞动力学演化的典型工具。我们对该模型的理论框架进行了拓展，用3味Nambu-Jona-Lasinio(NJL)模型描述部分子演化，并引入了重子、反重子、pi介子、及K介子的平均场势。其中，从NJL模型及其polyakov-loop扩展出发可以得到有效的QCD相图及夸克物质状态方程。我们基于拓展的多相输运模型研究了RHIC束流能量扫描实验中正反粒子椭圆流的劈裂。实验上正反核子和正反K介子的椭圆流劈裂对NJL拉氏量中的矢量耦合强度给出了约束，pi-和pi+介子的椭圆流劈裂对NJL拉氏量中的同位旋矢量耦合强度给出了约束。这些约束可以让我们进一步获取QCD相图及夸克物质状态方程的信息。
主要参考文献：
[1] J. Xu, L.W. Chen, C.M. Ko, and Z.W. Lin, Phys. Rev. C 85, 041901(R)...
Dr
Xiaofeng Luo
(Central China Normal University)
10/10/2019, 09:35
中高能核物理
Experimental confirmation of the QCD critical point is an excellent test of QCD theory in the non-perturbative region and a landmark of exploring the QCD phase structure.
It is one of the main goals of the RHIC Beam Energy Scan (BES) program. Fluctuations of conserved quantities, such as baryon, electric charge and strangeness numbers are sensitive observables
in relativistic heavy-ion...
Prof.
Zebo Tang
(University of Science and Technology of China)
10/10/2019, 10:30
中高能核物理
Heavy quark provides an excellent prob of the hot dense medium created in ultra-relativistic heavy-ion collisions due to its larger masses. The heavy flavor quark are dominantly produced before the quark-gluon plasma (QGP) formation and then transport in the medium and hadronization when the medium is cooling down. Measurements of open heavy flavor hadron production in ultra-relativistic...
Dr
XINYE PENG
(CCNU)
10/10/2019, 10:50
中高能核物理
Heavy quarks (charm and beauty) are a powerful probe of the Quark-Gluon Plasma (QGP) formed in high-energy heavy-ion collisions. They are produced in hard scattering processes on a timescale shorter than the QGP formation time and experience the whole system evolution. The measurement of the nuclear modification factor (RAA) of open heavy flavours can provide important information about the...
Mr
Fan Si
(University of Science and Technology of China)
10/10/2019, 11:10
中高能核物理
Heavy quarks (charm and beauty) are believed to be produced predominantly in hard scattering processes at early stage of the collisions before the QGP production so they can pass through the hot-dense medium completely, and their production yields can be calculated by perturbative-QCD, which makes them ideal probes for QGP. According to the theoretical prediction, energy loss of heavy quarks...
Qian Yang
(Shandong University)
10/10/2019, 11:30
中高能核物理
The production of heavy quarkonia has been extensively used to probe the Quark-Gluon Plasma (QGP) created in heavy ion collisions. The suppression of 𝐽/$\psi$ in a deconfined medium due to Debye color screening of the charm quark potential has been proposed as a signature of the QGP formation. Interpretation of 𝐽/$\psi$ suppression requires good understandings of its production mechanism in...
Pengfei Pengfei Wang
(USTC)
10/10/2019, 11:50
中高能核物理
Measurements of quarkonium production play an important role in understanding the properties of the Quark-Gluon Plasma (QGP) created in
relativistic heavy-ion collisions. Quarkonium suppression in the medium
due to the color screening effect has been proposed as a direct signature
of the QGP formation. However, other effects, such as cold nuclear matter (CNM) effects and regeneration, add...
Prof.
Fan Wang
(Nanjing University)
10/10/2019, 13:30
中高能核物理
The prevailing idea about nuclear force is due to meson exchange, either phenomenological one boson
exchange model or chiral perturbation effective theory both describe the NN interaction data quite well.
However they can not explain a long standing fact, as emphasized by Bohr and Mottelson in their Nuclear
structure book, the nuclear force is quite similar to molecular force except the...
Prof.
Lianrong Dai
(Liaoning Normal University)
10/10/2019, 13:50
中高能核物理
First I will present an novel approach on tau decay recently developed, using the basic weak interaction and angular momentum algebra to relate the different processes. The formalism also leads to a different interpretation of the role played by G-parity in these decays. We compare our results with experiment and other theoretical approaches for rates and invariant mass distributions and...
Dr
CHI YANG
(Shandong University)
10/10/2019, 14:10
中高能核物理
A primary goal of relativistic heavy-ion physics is to study the fundamental
properties of the created hot and dense medium. This medium is expected to emit thermal radiation in the form of dileptons and direct photons. Once produced, dileptons and direct photons traverse the medium with minimum interactions. This makes them ideal electromagnetic probes of the medium evolution by selecting...
王妹 查
(中国科学技术大学近代物理系)
10/10/2019, 14:30
中高能核物理
The coherent photon-nucleus and photon-photon interactions has been studied in detail to probe the gluon distribution in nucleus and to test QED via relativistic heavy-ion collisions. These kind of interactions are traditionally thought to be only exist in ultra-peripheral collisions (UPC), where there is no hadronic interactions. Recently, significant excess of $J/\psi$ yield and dielectron...
Mr
Junjie He
(Shanghai Institute of Applied Physics)
10/10/2019, 15:10
中高能核物理
Through $^{12}$C + $^{197}$Au collisions at $\sqrt{s_{NN}} =$ 200 GeV using a multiphase transport (AMPT) model, the azimuthal angle dependences of the Hanbury Brown-Twiss (HBT) radii relative to the second- and third-order participant plane from $\pi$-$\pi$ correlations are discussed.
Three initial geometric configurations of $^{12}$C, namely three-$\alpha$-cluster triangle,...
Shi Pu
(University of Science and Technology of China)
10/10/2019, 16:00
中高能核物理
We study relativistic magnetohydrodynamics with longitudinal boost invariance in the presence of chiral magnetic effects and finite electric conductivity. With initial magnetic fields parallel or antiparallel to electric fields, we derive the analytic solutions of electromagnetic fields and the chiral number and energy density in an expansion of several parameters determined by initial...
ling huang
(中科院上海应用物理研究所)
10/10/2019, 16:20
中高能核物理
The chiral magnetic effect is a good observable to investigate the topological and electromagnetic properties of the QGP. But the $\gamma$ correlator, a common observable used to detect the CME, contains both contribution from the CME and its background. This observable can not identify the CME from its background. Recently, a new observable of $R_{\Psi_{m}}$ has been proposed, which is...
yilin cheng
(Shanghai Institute of Applied Physics, Chinese Academy of Sciences)
10/10/2019, 16:40
中高能核物理
Electromagnetic fields produced in relativistic heavy-ion collisions are affected by the asymmetry of the projectile-target combination as well as the different initial configurations of the nucleus.
In this study, the results of the electric and magnetic fields produced for different combinations of ions, namely $^{12}$C + $^{197}$Au, $^{24}$Mg + $^{197}$Au, $^{64}$Cu + $^{197}$Au, and...
梳苏 施
(Central China Normal University)
10/10/2019, 17:00
中高能核物理
The flow harmonics (vn) especially, the first order (directed flow, v1) and the second order (elliptic flow, v2) are the sensitive probes to study QCD matter formed in heavy-ion collisions. Hydrodynamic models suggest that the double sign change of v1 slope (dv1/dy) at midrapidity for net baryon as a function of √sNN is a signature of the first-order phase transition. The light nuclei and...
Dr
Pengcheng Li
(Lanzhou University&Huzhou University)
10/10/2019, 17:20
中高能核物理
最近，STAR合作组在相对论重离子对撞机(RHIC)的一期束流能量扫描实验(BES-Ⅰ)中观测到了正反粒子的椭圆流($v_{2}$)劈裂现象，质子与反质子之间的椭圆流差随着入射能量$\sqrt{s_{NN}}$ （净重子密度）的升高（降低）而减小。对此不同的理论组利用不同的模型给出了不同的解释。
基于极端相对论量子分子动力学(UrQMD)模型，我们通过为预形成粒子考虑一个类似于已形成粒子之间的平均场势修正来部分实现预形成粒子之间的相互作用，由此为碰撞早期提供更大的压强以及粒子间更紧密的相互关联使得反质子可以更早地被挤出火球区域。我们的计算结果可以较好的描述实验测得的质子的椭圆流以及质子与反质子之间的椭圆流差及相对椭圆流差。同时我们将能区拓展到NICA能区($\sqrt{s_{NN}}=5\sim11$...
Maowu Nie
(Shandong University)
10/10/2019, 17:40
中高能核物理
小系统中的长程方位角关联的起源问题是目前相对论重离子碰撞领域的热点之一。目前的研究主要集中
于如下争论：即这种长程关联导致的集体流是由碰撞开始前的初始动量各向异性导致的，还是由于反映
初始几何形状的末态相互作用导致的。为了具体厘清小系统中集体流的成因，我们基于多相输运模型，
通过可控的方式引入所谓“初始流”，从而在输运模型中同时研究初始和末态相互作用效应。我们的研究
结果表明末态观测到的集体流，原则上会同时包含上述两种贡献，在高多重数区域，初始流的贡献有限，
但是在低多重数区域，初始流的贡献则尤为显著。因此，对于小系统中观测到的集体流不能只是孤立地
认为是由几何形状响应导致的，也应该考虑初始效应的贡献。
Prof.
Guo-yun Shao
(Xi'an Jiaotong University)
11/10/2019, 08:30
中高能核物理
In this talk, we will discuss the relation between density fluctuations and phase structure of strongly interacting matter. We focus on the phase transition in the high-density region where a non-equilibrium first-order transition possibly be trigged with lower collision energies. On the other hand, we will discuss the QCD phase structure in the presence of an background magnetic field. We...
Prof.
兆庆 冯
(华南理工大学)
11/10/2019, 08:50
中高能核物理
Formation mechanism of hyperfragments with strangeness s=-1 and s=-2 in heavy-ion collisions and with hadron induced reactions was investigated within a microscopic transport model. Dynamics of pseudoscalar mesons and hyperons is modeled within the transport model, in which all possible reaction channels for creating hyperons such as the elastic scattering, resonance production and decay,...
Pengyao Cui
(Central China Normal University)
11/10/2019, 09:10
中高能核物理
The $p_{\rm T}$ dependence of the baryon-to-meson yield ratio in hadronic and nuclear collisions is sensitive to the collective expansion of the system, the partonic recombination into hadrons, the jet fragmentation and hadronization.
In the region 2 < $p_{\rm T}$ < 6 GeV/$c$, this ratio for inclusive yields is significantly enhanced at high multiplicity in small collision systems, such as pp...
Dr
Fengxian Liu
(China University of Geosciences)
11/10/2019, 09:30
中高能核物理
Production of light (anti)nuclei ( $\rm d$, $\rm\overline d$, $\rm ^3He$, $\rm^3\overline {He}$, $\rm ^4He$, and $\rm^4\overline {He}$) and (anti)hypertriton nuclei ($\rm ^3_{\Lambda}H$ and $\rm ^3_{\overline \Lambda}\overline H$ ) are investigated using the dynamically constrained phase-space coalescence model based on the final-state hadrons generated by the PACIAE model in Cu+Cu collisions...
Mr
Baochi Fu
(Peking University)
11/10/2019, 09:50
中高能核物理
In this model, as a physical dynamic approach, AMPT is used to generate initial energy, velocity and net baryon density profile as the initial condition of hydrodynamics. The initial flow plays an important role especially at BES energies, where we find harder transverse momentum spectra of final particles.
Based on this model, we also investigated the global and local structure of...
Zhenyu Chen
(Shandong University)
11/10/2019, 10:30
中高能核物理
In ultra-relativistic collisions of large, heavy nuclei (e.g. Au or Pb), a new state of nuclear matter consisting of liberated quarks and gluons is formed at a temperature of trillion Kelvins. This state of matter, commonly referred to as Quark Gluon Plasma (QGP), was discovered and confirmed at the Relativistic Heavy Ion Collider (BNL) and the Large Hadron Collider (CERN). The QGP was found...
Dr
松 张
(Fudan University)
11/10/2019, 10:50
中高能核物理
报告介绍相对论重离子碰撞中集体流、HBT关联、手征电磁场的计算，讨论在不同碰撞系统下这些可观测量与碰撞系统初始几何构型的关联，建议通过系统扫描实验鉴别alpha团簇结构存在的可能性。
Dr
LongGang Pang
(CCNU)
11/10/2019, 11:10
中高能核物理
深度学习是目前最好的模式识别算法。通过可微分的误差向后传递，深度学习可以在任意两组存在连续几何变换的数据集之间建立映射。我们使用34层的残差神经网络，在变形核与变形核的高能碰撞模拟末态，与核的变形因子之间建立映射。深度学习成功从碰撞末态粒子的个数与各向异性流之间的关系中，定量提取碰撞核的变形因子绝对值。我们设计了回归注意力掩码算法，来可视化深度神经网络在做出决策时的关注区域。神经网络的注意力区域显示，全重叠碰撞对大的核变形因子敏感，而半重叠碰撞，对所有的核变形因子敏感。此研究应该可以推广到低能核碰撞，从大量低能核核碰撞末态粒子的动量分布（同位旋分布），提取碰撞核的核子密度分布，中子皮等信息。
Yayun He
(Central China Normal University)
11/10/2019, 11:30
中高能核物理
The observed suppression of inclusive jets in heavy-ion collisions at LHC has a very weak $p_{T}$ dependence over a large range of $p_{T}$ = 50-1000 GeV and is almost independent of the colliding energy, though the initial energy density of the formed QGP has increased significantly from $\sqrt{s}$ = 2.76 to 5.02 TeV. This interesting phenomenon is fully investigated in the linear Boltzmann...
