Symmetry Breaking in the Strong Interaction – The Chiral Magnetic Effect

作     者：WANG Fuqiang 王福强

作者机构：School of ScienceHuzhou UniversityHuzhou 313000ZhejiangChina 

出 版 物：《原子核物理评论》 (Nuclear Physics Review)

年 卷 期：2024年第41卷第1期

页      面：1-10页

学科分类：08[工学] 0827[工学-核科学与技术] 082701[工学-核能科学与工程] 

基　　金：国家自然科学基金资助项目(12035006,12075085) 科技部资助项目(2020YFE020200) 

主　　题：chiral magnetic effect charge separation Δγcorrelator flow-induced background nonflow 

摘      要：The chiral magnetic effect (CME) refers to a charge separation along a strong magnetic field due to an imbalanced chirality of quarks from interactions with the vacuum topological gluon field. This chiral anomaly is a fundamental property of quantum chromodynamics (QCD) and, therefore, an observation of the CME would have far-reaching impact on our understanding of QCD and Nature. The measurements of the CME-sensitive azimuthal correlator Δγ observable in heavy-ion collisions are contaminated by a major background induced by elliptic flow anisotropy. Several novel approaches have been carried out, including a dedicated isobar collision program, to address this flow-induced background. Further background effects, arising from nonflow correlations, have been studied. While the isobar data are consistent with zero CME signal with an upper limit of 10% of the measured Δγ, the Au+Au midcentral data suggest a positive CME signal on the order of 10% of the measured Δγ with a significance of ~2 standard deviations. Future increased statistics and improved detector capability should yield a firm conclusion on the existence (or the lack) of the CME in relativistic heavy-ion collisions.