THE CRITICAL-POINTS OF STRONGLY COUPLED LATTICE QCD AT NONZERO CHEMICAL-POTENTIAL

We study QCD at nonzero quark density, zero temperature, infinite coup ling using the Glasgow algorithm. An improved complex zero analysis gi ves a critical point mu(c) in agreement with that of chiral symmetry r estoration computed with strong coupling expansions, and monomer-dimer simulations. We observe, however, two unphysical critical points: the onset for the number density mu(0), and mu(s) the saturation threshol d, coincident with pathological onsets observed in past quenched QCD c alculations. An analysis of the probability distributions for particle number supports our physical interpretation of the critical point mu( c), and offers a new intepretation of mu(0), which confirms its unphys ical nature. The perspectives for future lattice QCD calculations of t he properties of dense baryonic matter are briefly discussed. [S0556-2 821(97)02121-8].