The finite temperature transition for 3-flavour lattice QCD at finite isospin density

We simulate 3-flavour lattice QCD with a small chemical potential mu(I) for isospin, at temperatures close to the finite temperature transition. Using quark masses just above the critical mass for zero chemical potential, we determine the position of the transition from hadronic matter to a quark-gluon plasma as a function of mu(I). We see evidence for a critical endpoint where the transition changes from a crossover to a first-order transition as mu(I) is increased. We argue that QCD at finite mu(I) and QCD at finite quark-number chemical potential p should behave similarly in this region.