Lattice gauge theory simulations at nonzero chemical potential in the chiral limit

A well known feature of lattice QCD simulations at finite density is that the onset of critical behaviour appears to be controlled by the pion mass rather than that of the lightest baryon. We have therefore investigated a new approach which has two important features. Firstly, we add a four-fermi term to the standard staggered fermion SU(3) QCD lattice action. Secondly this approach allows us to study the behaviour of the theory in the chiral limit. In this limit the pion is massless. Results are presented for simulations in the chiral limit on 44 and 64 lattices at strong and intermediate gauge couplings respectively and for varying four-fermi couplings. (orig.)