Discussion of thermodynamic features within the PNJL model  

作　　者：Jin-Li Zhang Cheng-Ming Li Hong-Shi Zong 张金利;李程明;宗红石(Department of Physics, Nanjing University;Joint Center for Particle,Nuclear Physics and Cosmology;State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, CAS)

机构地区：[1]Department of Physics,Nanjing University,Nanjing 210093,China [2]Joint Center for Particle,Nuclear Physics and Cosmology,Nanjing 210093,China [3]2.State Key Laboratory of Theoretical Physics,Institute of Theoretical Physics,CAS,Beijing 100190,China

出　　处：《Chinese Physics C》2018年第12期32-43,共12页中国物理C（英文版）

基　　金：Supported by National Natural Science Foundation of China(11475085 11535005 11690030,11805097);National Major state Basic Research and Development of China(2016YFE0129300);Jiangsu Provincial Natural Science Foundation of China(BK20180323)

摘　　要：We discuss some thermodynamical features of a QCD system within the two-flavor Polyakov loop ex- tended Nambu Jona-Lasinio （PNJL） model. Several thermodynamical quantities of interest （pressure, energy density, specific heat, speed of sound, etc.） are investigated and discussed in detail with two different forms of Polyakov loop potential. The effective coupling strength G incorporating a quark feedback （quark condensate） through operator product expansion is also discussed, as well as the relationship between color deconfinement and chiral phase crossover. We find that some thermodynamical quantities have quite different behavior for different Polyakov loop potentials. By changing the characteristic temperature To of the pure Yang-Mills feld, we find that when To becomes small, color deconfinement might happen earlier than chiral phase crossover, while their relationship can be determined via some thermodynamical quantities. Furthermore, the behavior of the thermodynamical quantities is quite different in the two different forms of Polyakov loop potential studied. Especially, one of the potentials, specific heat, has two peaks, which correspond to color deconfinement and chiral phase crossover respectively. This interesting phenomenon may shed some light on whether the inflection points at the same temperature or not for lattice QCD and of the chiral condensate and deconfinement transitions happen experimental studies.We discuss some thermodynamical features of a QCD system within the two-flavor Polyakov loop ex- tended Nambu Jona-Lasinio （PNJL） model. Several thermodynamical quantities of interest （pressure, energy density, specific heat, speed of sound, etc.） are investigated and discussed in detail with two different forms of Polyakov loop potential. The effective coupling strength G incorporating a quark feedback （quark condensate） through operator product expansion is also discussed, as well as the relationship between color deconfinement and chiral phase crossover. We find that some thermodynamical quantities have quite different behavior for different Polyakov loop potentials. By changing the characteristic temperature To of the pure Yang-Mills feld, we find that when To becomes small, color deconfinement might happen earlier than chiral phase crossover, while their relationship can be determined via some thermodynamical quantities. Furthermore, the behavior of the thermodynamical quantities is quite different in the two different forms of Polyakov loop potential studied. Especially, one of the potentials, specific heat, has two peaks, which correspond to color deconfinement and chiral phase crossover respectively. This interesting phenomenon may shed some light on whether the inflection points at the same temperature or not for lattice QCD and of the chiral condensate and deconfinement transitions happen experimental studies.

关 键 词：DECONFINEMENT specific heat transition temperature 

分 类 号：O572.33[理学—粒子物理与原子核物理]