论文标题
TC上方QCD中的手性磁效应和手性自旋对称性
The chiral magnetic effect and the chiral spin symmetry in QCD above Tc
论文作者
论文摘要
手性磁效应（CME）是通过轴向异常连接的确切陈述。系统中的电流由相互作用的费米子和仪表场和手性不平衡组成，并将其放入强大的外部磁场中。在QCD中磁性诱导的电流的实验搜索在伪离子碰撞的高度温度提示上，尽管尚未结论，但诱导的电流很小或消失。这意味着可以通过拓扑波动产生的QCD的手性不平衡最多很小。在这里，我们提出了在TC上方QCD中缺乏（小）手性失衡的最普遍的原因。最近在晶格上发现，TC上方的QCD大约是手性旋转（CS）对称的，对称性破裂的水平为几％。 CS转换混合了夸克的右手和左手组件。然后，精确的CS对称性将不需要任何手性失衡。因此，大概的CS对称性最多可以在TC上方的QCD中最小的手性失衡。因此，在重离子碰撞中观察到的磁诱导电流的缺失或小，可以视为TC上方CS对称性出现的实验证据。
The chiral magnetic effect (CME) is an exact statement that connects via the axial anomaly the electric current in a system consisting of interacting fermions and gauge field with chirality imbalance that is put into a strong external magnetic field. Experimental search of the magnetically induced current in QCD in heavy ion collisions above a pseudocritical temperature hints, though not yet conclusive, that the induced current is either small or vanishing. This would imply that the chirality imbalance in QCD above $T_c$ that could be generated via topological fluctuations is at most very small. Here we present the most general reason for absence (smallness) of the chirality imbalance in QCD above Tc. It was recently found on the lattice that QCD above Tc is approximately chiral spin (CS) symmetric with the symmetry breaking at the level of a few percent. The CS transformations mix the right- and left-handed components of quarks. Then an exact CS symmetry would require absence of any chirality imbalance. Consequently an approximate CS symmetry admits at most a very small chirality imbalance in QCD above Tc. Hence the absence or smallness of an magnetically induced current observed in heavy ion collisions could be considered as experimental evidence for emergence of the CS symmetry above Tc.
