Lattice QCD at finite isospin density and/or temperature

Abstract

We simulate two-flavour lattice QCD with at a finite chemical potential $μ_I$ for isospin, and finite temperature. At small $μ_I$, we determine the position of the crossover from hadronic matter to a quark-gluon plasma as a function of $μ_I$. At larger $μ_I$ we observe the phase transition from the superfluid pion-condensed phase to a quark-gluon plasma, noting its change from second order to first order as $μ_I$ is increased. We also simulate two-flavour lattice QCD at zero quark mass, using an action which includes an additional 4-fermion interaction, at temperatures close to the chiral transition on $N_t=8$ lattices.

3 pages LaTex, 3 postscript figures. Parallel talk at Lattice2003(nonzero)