  We compute by numerical integration of the Dirac equation the number of
quark-antiquark pairs produced in the classical color fields of colliding
ultrarelativistic nuclei. Results for the dependence of the number of quarks on
the strength of the background field, the quark mass and time are presented. We
also perform several tests of our numerical method. While the number of qqbar
pairs is parametrically suppressed in the coupling constant, we find that in
this classical field model it could even be compatible with the thermal ratio
to the number of gluons.
