  We consider an alternative mechanism for the production of the cosmic
microwave background (CMB) radiation. It is basically due to vacuum pair
creation (VPC) of vector bosons (W and Z) as a consequence of a rapid W and Z
mass generation during the electroweak phase transition in the early Universe.
The mechanism is as follows: after their pair crreation, the vector bosons may
either annihilate directly into photons or decay into leptons and quarks which
subsequently annihilate as lepton-antilepton and quark-antiquark pairs into
photons. Preliminary estimates show that the number of CMB photons obtained
this way can be sufficient to explain the presently observed CMB photon
density. In this contribution we present an exactly soluble model for vacuum
pair creation kinetics.
