标题： 物质中的手征对称性 显示英文标题

标题： Chiral symmetry in matter

摘要： 软π子定理被用来展示手征对称性如何约束低动量π介子对夸克凝聚、π介子衰变常数以及强子质量的贡献，这些都被认为是物质中部分手征对称性恢复的信号。 对于π介子气体，这些贡献具有T²阶项；而对于冷核物质，则具有m_π阶项，在所有三种情况下系数各不相同，表明物质中这些量的变化之间没有简单的关联。 特别是，这些贡献在矢量介子和核子的质量中不存在，因此这些质量不能简单地表示为夸克凝聚的函数。 更普遍地说，由低动量π介子引起的夸克凝聚的部分不应与手征对称性的部分恢复联系起来。 显示英文摘要

摘要： Soft-pion theorems are used to show how chiral symmetry constrains the contributions of low-momentum pions to the quark condensate, the pion decay constant and hadron masses, all of which have been proposed as signals of partial restoration of chiral symmetry in matter. These have contributions of order T^2 for a pion gas or of order m_pi for cold nuclear matter, which have different coefficients in all three cases, showing that there are no simple relations between the changes to these quantities in matter. In particular, such contributions are absent from the masses of vector mesons and nucleons and so these masses cannot scale as any simple function of the quark condensate. More generally, pieces of the quark condensate that arise from low-momentum pions should not be associated with partial restoration of chiral symmetry.