Abstract
We simulate 2-flavor lattice QCD at finite isospin chemical potential , for temperatures close to the finite temperature transition from hadronic matter to a quark-gluon plasma. The dependence of the transition coupling is observed and used to estimate the decrease in the transition temperature with increasing . These simulations are performed on an lattice at three different quark masses. Our estimate of the magnitude of the fluctuations of the phase of the fermion determinant at small quark-number chemical potential , suggest that the position of the small and small transitions should be the same for , and we argue that the nature of these transitions should be the same. For all the smoothness of these transitions and the values of the Binder cumulant , indicate that these transitions are mere crossovers, and show no sign of a critical endpoint corresponding to that expected at finite . This suggests that this finite critical endpoint, if it exists, lies at over the considered range of quark masses. For and a small isospin () breaking term , we do find evidence of a critical endpoint which would indicate that, for , there is a tricritical point on the phase boundary where the pion condensate evaporates, where this phase transition changes from second to first-order.
9 More- Received 23 July 2004
DOI:https://doi.org/10.1103/PhysRevD.70.094501
©2004 American Physical Society