We discuss the nature of the phase transition for lattice QCD at finite temperature and density. We propose a method to calculate the canonical partition function by fixing the total quark number introducing approximations allowed in the low density region. An effective potential as a function of the quark number density is discussed from the canonical partition function. We analyze data obtained in a simulation of two-flavor QCD using p4-improved staggered quarks with bare quark mass m/T=0.4 on a 163×4 lattice. The results suggest that the finite density phase transition at low temperature is of first order.
@article{arxiv.0804.3227,
title = {Canonical partition function and finite density phase transition in lattice QCD},
author = {Shinji Ejiri},
journal= {arXiv preprint arXiv:0804.3227},
year = {2009}
}