https://doi.org/10.1140/epjc/s10052-014-2782-x
Regular Article - Theoretical Physics
The Wigner solution and QCD phase transitions in a modified PNJL model
1
Department of Physics, Key Laboratory of Modern Acoustics, MOE, Institute of Acoustics, Nanjing University, Nanjing, 210093, China
2
Department of Physics, Nanjing University, Nanjing, 210093, China
3
Joint Center for Particle, Nuclear Physics and Cosmology, Nanjing, 210093, China
4
State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, CAS, Beijing, 100190, China
5
Department of Physics, School of Science, Linyi University, Linyi, 276005, People’s Republic of China
6
Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, MA , 02139, USA
* e-mail: zonghs@chenwang.nju.edu.cn
Received:
18
November
2013
Accepted:
14
February
2014
Published online:
25
February
2014
By employing some modification to the widely used two-flavor Polyakov-loop extended Nambu–Jona–Lasinio (PNJL) model, we discuss the Wigner solution of the quark gap equation at finite temperature and zero quark chemical potential beyond the chiral limit, and then we try to explore its influence on the chiral and deconfinement phase transitions of QCD at finite temperature and zero chemical potential. The discovery of the coexistence of the Nambu and the Wigner solutions of the quark gap equation with nonzero current quark mass at zero temperature and zero chemical potential, as well as their evolutions with temperature, is very interesting for the studies of the phase transitions of QCD. According to our results, the chiral phase transition might be of first order (while the deconfinement phase transition is still a crossover, as in the normal PNJL model), and the corresponding phase transition temperature is lower than that of the deconfinement phase transition, instead of coinciding with each other, which are not the same as the conclusions obtained from the normal PNJL model. In addition, we also discuss the sensibility of our final results on the choice of model parameters.
© The Author(s), 2014
