Finite volume effects on the QCD chiral phase transition in the finite size dependent Nambu-Jona-Lasinio model * * Supported by the National Natural Science Foundation of China (11475085, 11535005, 11690030) and the National Major state Basic Research and Development (2016YFE0129300)

Abstract

The effective Lagrangian of a finite volume system should, in principle, depend on the system size. In the framework of the Nambu-Jona-Lasinio (NJL) model, by considering the influence of quark feedback on the effective coupling, we obtain a modified NJL model so that its Lagrangian depends on the volume. Based on the modified NJL model, we study the influence of finite volume on the chiral phase transition at finite temperature, and find that the pseudo-critical temperature of crossover is much lower than that obtained in the normal NJL model. This clearly shows that the volume dependent effective Lagrangian plays an important role in the chiral phase transitions at finite temperature.