BARYOGENESIS DURING REHEATING IN NATURAL INFLATION AND COMMENTS ON SPONTANEOUS BARYOGENESIS

We calculate the baryon asymmetry created by the decay of a pseudo Nam bu-Goldstone boson (PNGB) whose interactions violate baryon number con servation. Our results are in disagreement with previous results in th e original spontaneous baryogenesis models for the asymmetry produced by the decay of an oscillating scalar field with B-number-violating de rivative couplings; we find that the net baryon number density is prop ortional to theta(i)(3), where theta(i) is the amplitude of the PNGB f ield in natural inflation at the onset of reheating. While our calcula tion of the asymmetry is carried out in the context of natural inflati on our approach is generally valid for baryogenesis models using decay ing classical fields. We include a complete derivation of the number d ensity of particles produced by the decay of a classical scalar field. [S0556-2821(97)07422-5].