Nambu–Jona-Lasinio model in a sphere

Zheng Zhang,Chao Shi,Hong-Shi Zong

doi:10.1103/physrevd.101.043006

Abstract

We study the chiral phase transition of the two flavor Nambu-Jona-Lasinio (NJL) model in a sphere with the MIT boundary condition. We find that the MIT boundary condition results in much stronger finite size effects than the antiperiodic boundary condition. Our work may be helpful to study the finite size effects in heavy-ion collision in a more realistic way.

Highlights

The finite size effects in quantum chromodynamics (QCD) have caused much theoretical interest for more than two decades
We find that the spherical MIT boundary condition results in stronger finite size effects than the antiperiodic boundary condition
It is believed that these experiments could produces the quark-gluon plasma (QGP), a phase of matter believed to exist in the early Universe

Summary

INTRODUCTION

The finite size effects in quantum chromodynamics (QCD) have caused much theoretical interest for more than two decades. In most existing studies of finite size effects in QCD, the systems are usually treated as a box. There are several studies [6,7,31,32,33] treating the system as a sphere, and the multiple reflection expansion (MRE) method [34] is used. To consider finite size effects, we replace the integral over spatial momenta with a sum over discrete momentum modes. This “brute force method” has no difficulty to be applied for the sphere case, though the calculation is more complicated. We will use this method to study the chiral phase transition of NJL model in a sphere.

NJL MODEL IN A SPHERE WITH THE MIT BOUNDARY CONDITION

CHIRAL PHASE TRANSITION OF THE NJL MODEL IN A SPHERE

SUMMARY