  We present results of a Monte Carlo simulation of a three dimensional
Gross-Neveu model with SU(2)xSU(2) chiral symmetry at non-zero baryon chemical
potential mu, corresponding to non-zero baryon density. For mu sufficiently
large there is a sharp transition between a phase where the chiral symmetry is
broken by a condensate <qbar q> and one where the global U(1) baryon number
symmetry appears to be broken by a scalar diquark condensate <qq>. There is
also tentative evidence for the formation of a weaker pseudoscalar diquark
condensate in the high density phase, which violoates parity.
