GUT Baryogenesis after Preheating: Numerical Study of the Production and Decay of X-bosons

We perform a fully non-linear calculation of the production of supermassive Grand Unified Theory (GUT) X bosons during preheating, taking into account the fact that they are unstable with a decay width Γ X. We show that parametric resonance does not develop if Γ X is larger than about 10 −2 m X. We compute the nonthermal number density of superheavy bosons produced in the preheating phase and demonstrate that the observed baryon asymmetry may be explained by GUT baryogenesis after preheating if Γ X is smaller than about 10 −3 m X .