标题： 奇数宇称泡在热QCD中 显示英文标题

标题： Parity odd bubbles in hot QCD

摘要： 我们考虑大颜色数极限下的SU(N)规范理论的拓扑易感性，$N \to \infty$。 在非零温度下，拓扑易感性的行为取决于禁闭相变的阶数。 最有趣的情况是，当$T=T_d$时，禁闭相变是二阶的。 那么我们认为， 维滕的关系表明，在$T_d$处，拓扑易感性以可计算的方式消失。 如维滕所指出的，这意味着对于足够轻的夸克质量，在略低于$T_d$的温度下，可以出现类似于非零$\theta$区域——奇宇称气泡——的亚稳态。 实验上，奇宇称气泡具有显著的特征： $\eta'$介子，尤其是$\eta$介子，会变得很轻，并且大量产生。 此外，在奇偶性奇的泡中，通常被禁止的过程，如$\eta \to \pi^0 \pi^0$，是允许的。 检测奇偶性破坏最直接的方法是测量带电π介子的奇偶性奇全局不对称性，我们对此进行定义。 显示英文摘要

摘要： We consider the topological susceptibility for an SU(N) gauge theory in the limit of a large number of colors, $N \to \infty$. At nonzero temperature, the behavior of the topological susceptibility depends upon the order of the deconfining phase transition. The most interesting possibility is if the deconfining transition, at $T=T_d$, is of second order. Then we argue that Witten's relation implies that the topological susceptibility vanishes in a calculable fashion at $T_d$. As noted by Witten, this implies that for sufficiently light quark masses, metastable states which act like regions of nonzero $\theta$ --- parity odd bubbles --- can arise at temperatures just below $T_d$. Experimentally, parity odd bubbles have dramatic signatures: the $\eta'$ meson, and especially the $\eta$ meson, become light, and are copiously produced. Further, in parity odd bubbles, processes which are normally forbidden, such as $\eta \to \pi^0 \pi^0$, are allowed. The most direct way to detect parity violation is by measuring a parity odd global asymmetry for charged pions, which we define.