Implications of the isobar-run results for the chiral magnetic effect in heavy-ion collisions
Implications of the isobar-run results for the chiral magnetic effect in heavy-ion collisions
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DOI：
10.1103/physrevc.106.l051903
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发表时间：
2022-04
影响因子：
3.1
通讯作者：
D. Kharzeev;J. Liao;S. Shi
中科院分区：
文献类型：
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作者：
D. Kharzeev;J. Liao;S. Shi
手征磁效应（CME）是指在手征不平衡和外加磁场作用下，由量子反常引起的宏观输运现象。相对论重离子碰撞提供了在非阿贝尔等离子体中寻找CME的独特机会，其中手性不平衡是由类似于早期宇宙中发生的拓扑跃迁产生的。提出了在相对论重离子对撞机上进行同量异位素实验，将磁场驱动的CME信号从背景中分离出来。星星合作组织最近公布了这一重要实验的第一个盲分析结果。在预先定义的RuRu和ZrZr背景相同的假设下，结果与CME的存在以及所有现有的理论模型（无论是否包括CME）不一致。然而，在得出任何物理结论之前，必须考虑观察到的背景差异。在本文中，我们表明，一旦观测到的强子多重性和集体流的差异被定量考虑，星星的结果可能是一致的，一个有限的CME信号的贡献约为$（6.8\pm2.6）\%$。
Chiral magnetic effect (CME) is a macroscopic transport phenomenon induced by quantum anomaly in the presence of chiral imbalance and an external magnetic field. Relativistic heavy ion collisions provide the unique opportunity to look for CME in a non-Abelian plasma, where the chiral imbalance is created by topological transitions similar to those occurring in the Early Universe. The isobar run at Relativistic Heavy Ion Collider was proposed as a way to separate the possible CME signal driven by magnetic field from the background. The first blind analysis results from this important experiment have been recently released by the STAR Collaboration. Under the pre-defined assumption of identical background in RuRu and ZrZr, the results are inconsistent with the presence of CME, as well as with all existing theoretical models (whether including CME or not). However the observed difference of backgrounds must be taken into account before any physical conclusion is drawn. In this paper, we show that once the observed difference in hadron multiplicity and collective flow are quantitatively taken into account, the STAR results could be consistent with a finite CME signal contribution of about $(6.8\pm2.6)\%$.