夸克物质中的超子整体极化与矢量介子自旋排列  

Global polarization of hyperons and spin alignment of vector mesons in quark matters

作　　者：阮丽娟 许长补 杨驰 Ruan Li-Juan;Xu Zhang-Bu;Yang Chi(Department of Physics,Brookhaven National Laboratory,Upton 11973,USA;Key Laboratory of Particle Physics and Particle Irradiation(MOE),Institute of Frontier and Interdisciplinary Science,Shandong University,Qingdao 266237,China)

机构地区：[1]美国布鲁克海文国家实验室,物理系,美国厄普顿11973 [2]山东大学前沿交叉科学青岛研究院,粒子物理与粒子辐照教育部重点实验室,青岛266237

出　　处：《物理学报》2023年第11期13-18,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11890713,12075139);山东省自然科学基金(批准号:ZR2022JQ03);美国能源部科学办公室基金(批准号:DE-SC0012704,DE-FG02-10ER41666,DE-AC02-98CH10886)资助的课题.

摘　　要：相对论重离子对撞机RHIC上超子整体极化和矢量介子自旋排列的实验发现证实了近20年前提出的理论.该理论预言和实验测量开辟了一种从自旋这个新的自由度来研究高能重离子碰撞中产生的高温高密核物质特性的新途径.本文简略回顾了整体极化理论提出和实验发现,总结了现有大科学装置上的相关测量进展,以及国际上现有的多种理论解释.同时,简要介绍了STAR探测器近期升级所带来的物理机遇.Relativistic heavy ion collider(RHIC)as a dedicated nuclear facility has made a few major discoveries in physics.This year marks the 30th year STAR Collaboration formation and the 23th year of STAR detector operation and data collection at RHIC.In the last two decades,STAR has collected many datasets,exhibiting scientific versatility and flexibility of the RHIC facility.The total dataset in the first year is less than 1 million good events,and currently there are about 1 billion events per dataset.The Global Hyperon Polarization was proposed in 2004.This immediately prompted the STAR Collaboration to search for this phenomenon from the early datasets.The null results were presented at Quark Matter Conference in Shanghai in 2006 and subsequently published.Although there were peripheral and continuous efforts in the following decade,no positive result has been observed experimentally.This situation changed in the following decade with the upgrade of high data rate and time-of-flight(TOF)detector and the progress of the Beam Energy Scan Phase I(BES-I).The experimental discoveries of the global polarization of hyperons in 2017 and the spin alignment of vector mesons in 2023 at RHIC-STAR confirm the theory which was established nearly twenty years ago.The theory and these measurements open the way to studying the properties of the hot and dense nuclear matter created in high-energy heavy ion collisions from a new degree of freedom,spin.We briefly review these discoveries from the proposals of theory to the experimental measurements,and summarize the related measurements at the existing facilities and the theoretical explanations to the original proposal.The basic understanding and the original proposal are still valid and fundamental,that is,the angular momentum of system can transform into a spin effect observable in experiment.However,it appears that in each case a new model is needed to explain the new experimental observation.We need a more basic theory to help us unify all these spin related phenomena.Over the pa

关 键 词：相对论重离子对撞机 螺线管径迹谱仪 超子整体极化 矢量介子自旋排列 

分 类 号：O572.33[理学—粒子物理与原子核物理]