  We compute by numerical integration of the Dirac equation the number of
quark-antiquark pairs initially produced in the classical color fields of
colliding ultrarelativistic nuclei. While the number of qqbar pairs is
parametrically suppressed in the coupling constant, we find that in this
classical field model their production rate is comparable to the thermal ratio
of gluons/pairs = 9 N_f/32. After isotropization one thus would have
quark-gluon plasma in chemical equilibrium.
