有限温度和化学势下σ、π介子的质量  

The masses of σ、π mesons at finite temperature and chemical potential

作　　者：陈建兴[1] 黄俊文 郝正超 陈圆圆 CHEN Jianxing;HUANG Junwen;HAO Zhengchao;CHEN Yuanyuan(School of Physics and Electronic Technology,Liaoning Normal University,Dalian 116029,China)

机构地区：[1]辽宁师范大学物理与电子技术学院

出　　处：《辽宁师范大学学报（自然科学版）》2019年第4期450-456,共7页Journal of Liaoning Normal University:Natural Science Edition

摘　　要：利用一种重新求和方案,在Nf=2的NJL模型框架下,研究了标量σ介子、赝标量π介子的热质量.计算表明,随着温度的升高,σ介子的质量先下降,然后升高;π介子的质量一直随温度升高而增加.两种介子在温度约为0.2GeV时质量发生简并,这是手征对称性恢复的信号.π介子质量的连续变化表明相变是二阶的.化学势的提高对不同介子的质量的影响是不同的,且使手征对称性恢复提前.计算结果与其他有效模型的预言定性一致.By using a resummation method,in the frame of N_f=2NJL model,the thermal masses of the scalarσand pseudoscalarπmesons are investigated.The results show that with the increase of temperature,the mass of theσmeson drops first,then begins to increase,while the mass ofπincreases all the way with the temperature.Their masses become degenerated at temperature about 0.2 GeV,which signifies the chiral symmetry restoration.The mass ofπvaries continuously with temperature implies the chiral phase transion is a second order one.The enhance of chemical potential leads to different effects for the masses of different mesons,and advances the chiral symmetry restoration.Our results are consistent qualitatively with the results of other effective models.

关 键 词：σ和π的质量 NJL模型 OPT方法 手征相变 

分 类 号：O572.33[理学—粒子物理与原子核物理]