PUB - Publikationen an der Universität Bielefeld

Partition functions of two different matrix models for QCD with chemicalpotential are computed for an arbitrary number of quark and complex conjugateanti-quark flavors. In the large-N limit of weak nonhermiticity completeagreement is found between the two models. This supports the universality ofsuch fermionic partition functions, that is of products of characteristicpolynomials in the complex plane. In the strong nonhermiticity limit agreementis found for an equal number of quark and conjugate flavours. For a generalflavor content the equality of partition functions holds only for smallchemical potential. The chiral phase transition is analyzed for an arbitrarynumber of quarks, where the free energy presents a discontinuity of first orderat a critical chemical potential. In the case of nondegenerate flavors there isfirst order phase transition for each separate mass scale.