  We simulate the lattice Nambu--Jona-Lasinio (NJL) model in 3+1-dimensions at
non-zero baryon chemical potential (mu) and zero temperature (T) and treat the
results as phenomenologically relevant for cold, dense quark matter.
Measurements of the chiral condensate indicate a crossover in the thermodynamic
limit, whilst at high chemical potential and zero temperature we observe a
non-zero diquark condensate and a gap in the fermion dispersion relation, which
together provide evidence for BCS superfluidity. In particular, the size of gap
is found to be approximately 15% the value of the vacuum fermion mass and
roughly independent of mu in the chirally restored phase.
