The critical endpoint (CEP) and the phase structure are studied in the Polyakov-loop extended Nambu--Jona-Lasinio model in which the scalar type eight-quark (\sigma^4) interaction and the vector type four-quark interaction are newly added. The \sigma^4 interaction largely shifts the CEP toward higher temperature and lower chemical potential, while the vector type interaction does oppositely. At zero chemical potential, the \sigma^4 interaction moves the pseudo-critical temperature of the chiral phase transition to the vicinity of that of the deconfinement phase transition.
@article{arxiv.0710.2180,
title = {Critical endpoint in the Polyakov-loop extended NJL model},
author = {Kouji Kashiwa and Hiroaki Kouno and Masayuki Matsuzaki and Masanobu Yahiro},
journal= {arXiv preprint arXiv:0710.2180},
year = {2008}
}
Comments
13 pages, 6 figures embedded, accepted for publication in Phys. Lett. B