First order phase transition in finite density QCD using the modulus of the Dirac determinant

We report results of simulations of strong coupling, finite density QCD obtained within a MFA inspired approach where the fermion determinant in the integration measure is replaced by its absolute value. Contrary to the standard wisdom, we show that within this approach a clear signal for a first order phase transition appears with a critical chemical potential in extremely good agreement with the results obtained with the Glasgow algorithm. The modulus of the fermion determinant seems therefore to preserve some of the relevant physical properties of the system. We also analyze the dependence of our results on the quark mass, including both the chiral and large mass limit, and the theory in the quenched approximation. (C) 1998 Elsevier Science B.V. All rights reserved.