Cosmological baryon generation in the minimal Wise, Georgi and Glashow model

We discuss the cosmological baryon generation in the minimally extended SU(5) model of Wise, Georgi and Glashow that incorporates the Dine, Fischler and Srednicki mechanism for solving the strong CP problem. It has been, recently, pointed out that the usual scenario for baryon generation using the Higgs decays does not work in this model because of the strong restriction on the Yukawa couplings due to the Peccei-Quinn symmetry. However, we show that colored gauge boson decays play a major role in baryon production: indeed, interferences with one-loop diagrams provide a non-vanishing ΔB. Subsequent dilution effects are taken into account. The resulting cosmological baryon asymmetry is compatible with the observed ratio knsub(B)/s approx. equal to 10-10. (orig.)