Title: The impact of domain walls on the chiral magnetic effect in hot QCD matter Show Chinese title

Title: 畴壁对热QCD物质中手征磁效应的影响

Abstract: The Chiral Magnetic Effect (CME) -- the separation of positive and negative electric charges along the direction of the external magnetic field in quark-gluon plasma and other topologically non-trivial media -- is a consequence of the coupling of electrodynamics to the topological gluon field fluctuations that form metastable $CP$-odd domains. In phenomenological models it is usually assumed that the domains are uniform and the influence of the domain walls on the electric current flow is not essential. This paper challenges the latter assumption. A simple model consisting of a uniform spherical domain in a uniform time-dependent magnetic field is introduced and analytically solved. It is shown that (i) no electric current flows into or out of the domain, (ii) the charge separation current, viz. the total electric current flowing inside the domain in the external field direction, is a dissipative Ohm current, (iii) the CME effect can be produced either by the anomalous current or by the boundary conditions on the domain wall and (iv) the charge separation current oscillates in plasma long after the external field decays. These properties are qualitatively different from the CME in an infinite medium. Show Chinese abstract

Abstract: 手征磁效应（CME）——在夸克-胶子等离子体和其他拓扑非平凡介质中，正负电荷沿外加磁场方向的分离——是电动力学与形成亚稳态$CP$-奇域的拓扑胶子场涨落耦合的结果。在现象学模型中，通常假设这些域是均匀的，域壁对电流流动的影响并不重要。本文挑战了后一种假设。引入了一个由均匀球形域和均匀时变磁场组成的简单模型，并对其进行了解析求解。结果表明：（i）没有电流流入或流出该域，（ii）电荷分离电流，即在外场方向上流经域内的总电流，是一种耗散的欧姆电流，（iii）CME效应可以通过异常电流或域壁上的边界条件产生，（iv）在外部磁场衰减后很长一段时间内，电荷分离电流在等离子体中会发生振荡。这些特性与无限介质中的CME有定性上的不同。