九大原子核セミナー

2009年9月17日(木) 15:00

講師： 幸山　浩章　氏 (中央研究院)
演題：The Nambu Jona-Lasinio model with density dependent UA(1) anomaly

概要　：

Whether the phase transition from hadron to　colorsuperconducting　state is of the first order is an interesting question. To study this, we　use the Nambu　Jona-Lasinio model which is low energy effective theory of
quantum chromodynamics(QCD). In this work, we consider the density　dependent UA(1) anomaly and study the critical surface in the quark mass and chemical potential space. We have found that the surface shrinks when a quark chemical potential increases, which is the opposite result from the study by using usual NJL model. The difference comes from the density dependence of the UA(1) anomaly and our result is consistent to
the recent lattice QCD study. Our result suggest the restoration of the UA(1) anomaly at high density, which seems to be physically reasonable because a color superconductivity state may dominate at intermediate baryon density where the UA(1) anomaly should be negligible.