@article{oai:niigata-u.repo.nii.ac.jp:00002277, author = {Ejiri, S.}, issue = {7}, journal = {Physical Review D, Physical Review D}, month = {Oct}, note = {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 16 3 ×4 lattice. The results suggest that the finite density phase transition at low temperature is of first order.}, title = {Canonical partition function and finite density phase transition in lattice QCD}, volume = {78}, year = {2008} }