量子色动力学(Quantum Chromodynamics,QCD)相图结构和相变临界点是高能物理理论和实验的研究热点。相对论重离子碰撞是探索QCD相图结构、寻找QCD相变临界点的有力工具。美国布鲁克海文国家实验室的相对论重离子对撞机(Relativistic Hea...量子色动力学(Quantum Chromodynamics,QCD)相图结构和相变临界点是高能物理理论和实验的研究热点。相对论重离子碰撞是探索QCD相图结构、寻找QCD相变临界点的有力工具。美国布鲁克海文国家实验室的相对论重离子对撞机(Relativistic Heavy Ion Collider,RHIC)是目前世界上进行高能重离子碰撞的大型实验装置之一,其中的STAR(Solenoidal Tracker at RHIC)实验致力于高温高密条件下夸克胶子等离子体(Quark Gluon Plasma,QGP)性质以及QCD相结构的实验研究。本文着重介绍近年来RHIC-STAR能量扫描实验中运用守恒荷高阶矩和轻核产生寻找QCD相变临界点的研究进展,最后将对高重子密度区QCD相结构的未来研究做出展望。展开更多
相对论性重离子对撞的目的之一是寻找量子色动力学(Quantum Chromodynamics,QCD)临界终点(Critical End Point,CEP),实验中测到的净质子数扰动呈现出非单调的行为,这暗示了CEP的存在。本文使用了3味PNJL(Polyakov-loop Nambu-Jona-Lasin...相对论性重离子对撞的目的之一是寻找量子色动力学(Quantum Chromodynamics,QCD)临界终点(Critical End Point,CEP),实验中测到的净质子数扰动呈现出非单调的行为,这暗示了CEP的存在。本文使用了3味PNJL(Polyakov-loop Nambu-Jona-Lasinio)模型,沿着从实验数据中拟合的化学冻结线,计算了重子数扰动累积量之比C4/C2随对撞能量的变化。结果发现,基于平衡态假设,在对撞能量7.7~200 GeV范围内,随着对撞能量的降低,C4/C2先缓慢下降后上升,这与实验数据一致。这也暗示平衡态假设可以用于探索重离子对撞后系统的演化行为,揭示了相变线跟化学冻结线的关系对观测量的影响非常重要。展开更多
能量扫描理论合作组(Beam Energy Scan Theory Collaboration,BEST)的目标是建立一个可以描述美国相对论重离子对撞机(Relativistic Heavy-Ion Collider,RHIC)上第二期能量扫描实验的动力学框架。该实验有可能找到强相互作用相图上的临...能量扫描理论合作组(Beam Energy Scan Theory Collaboration,BEST)的目标是建立一个可以描述美国相对论重离子对撞机(Relativistic Heavy-Ion Collider,RHIC)上第二期能量扫描实验的动力学框架。该实验有可能找到强相互作用相图上的临界点。本文总结自2016年起,BEST合作组取得重要进展,并对未来探索中高密度区相图做了展望。展开更多
The two-particle momentum correlation is influenced by the nuclear force between two particles,which has been intensively studied for nucleons and nuclei,but not much for antinucleons or antinuclei.In this proceeding,...The two-particle momentum correlation is influenced by the nuclear force between two particles,which has been intensively studied for nucleons and nuclei,but not much for antinucleons or antinuclei.In this proceeding,we present our STAR measurements on momentum correlation function of antiproton-antiproton and proton-proton in Au+Au collisions at S_(NN)^(1/2)= 200 GeV at the Relativistic Heavy Ion Collider.Attractive nuclear force between two antiprotons is demonstrated,and the strong interaction parameters(the scattering length and the effective range) are determined.This measurement serves as an additional verification of CPT symmetry.The present information on the strong force in the antiproton-antiproton system provides a fundamental ingredient towards understanding the structure of more sophisticated antinuclei.展开更多
The zero degree calorimeter(ZDC) at RHICSTAR was installed in the year 2000.After running for more than 10 years,the performance of the STAR-ZDC cannot maintain a proper status because of the radiation damage.The ZDC ...The zero degree calorimeter(ZDC) at RHICSTAR was installed in the year 2000.After running for more than 10 years,the performance of the STAR-ZDC cannot maintain a proper status because of the radiation damage.The ZDC on RHIC-BRAHMS had been moved to STAR in 2011 after some tests.We present here the result of the tests as well as the physical performance of those ZDC modules between the 2011 and 2015 RHIC runs.The excellent energy resolution of the ZDC in heavy ion collision provides a good candidate for future detector development,such as the CSR experiment at CAS-Lanzhou facility.展开更多
基金supported by the National Natural Science Foundation of China (11775213, 12005220)the USTC Research Funds of the Double First-Class Initiative(YD2360002001)。
文摘量子色动力学(Quantum Chromodynamics,QCD)相图结构和相变临界点是高能物理理论和实验的研究热点。相对论重离子碰撞是探索QCD相图结构、寻找QCD相变临界点的有力工具。美国布鲁克海文国家实验室的相对论重离子对撞机(Relativistic Heavy Ion Collider,RHIC)是目前世界上进行高能重离子碰撞的大型实验装置之一,其中的STAR(Solenoidal Tracker at RHIC)实验致力于高温高密条件下夸克胶子等离子体(Quark Gluon Plasma,QGP)性质以及QCD相结构的实验研究。本文着重介绍近年来RHIC-STAR能量扫描实验中运用守恒荷高阶矩和轻核产生寻找QCD相变临界点的研究进展,最后将对高重子密度区QCD相结构的未来研究做出展望。
文摘能量扫描理论合作组(Beam Energy Scan Theory Collaboration,BEST)的目标是建立一个可以描述美国相对论重离子对撞机(Relativistic Heavy-Ion Collider,RHIC)上第二期能量扫描实验的动力学框架。该实验有可能找到强相互作用相图上的临界点。本文总结自2016年起,BEST合作组取得重要进展,并对未来探索中高密度区相图做了展望。
基金supported in part by the National Natural Science Foundation of China(No.11421505)the Major State Basic Research Development Program in China(No.2014CB845401)
文摘The two-particle momentum correlation is influenced by the nuclear force between two particles,which has been intensively studied for nucleons and nuclei,but not much for antinucleons or antinuclei.In this proceeding,we present our STAR measurements on momentum correlation function of antiproton-antiproton and proton-proton in Au+Au collisions at S_(NN)^(1/2)= 200 GeV at the Relativistic Heavy Ion Collider.Attractive nuclear force between two antiprotons is demonstrated,and the strong interaction parameters(the scattering length and the effective range) are determined.This measurement serves as an additional verification of CPT symmetry.The present information on the strong force in the antiproton-antiproton system provides a fundamental ingredient towards understanding the structure of more sophisticated antinuclei.
基金supported by the Major State Basic Research Development Program in China(2014CB845400)the National Natural Science Foundation of China(Nos.11421505,11520101004,11322547,and 11275250)
文摘The zero degree calorimeter(ZDC) at RHICSTAR was installed in the year 2000.After running for more than 10 years,the performance of the STAR-ZDC cannot maintain a proper status because of the radiation damage.The ZDC on RHIC-BRAHMS had been moved to STAR in 2011 after some tests.We present here the result of the tests as well as the physical performance of those ZDC modules between the 2011 and 2015 RHIC runs.The excellent energy resolution of the ZDC in heavy ion collision provides a good candidate for future detector development,such as the CSR experiment at CAS-Lanzhou facility.
