Gauge-Mediated Curvature of the Flat Directions During Preheating

Abstract

Usually one expectes the inflaton field to be coupled to some gauge-charged particles allowing for its decay during reheating. Such particles then play a role of the messengers for the gauge-mediated supersymmetry breaking during and (shortly) after the inflation and radiatively induce soft masses to all other $D$-flat directions. We show that during the preheating stage this gauge-mediated soft masses are typically much greater than the Hubble parameter during inflation. The dramatic role is played by the supersymmetry (SUSY) breaking due to the parametric resonance effect, which ensures that the inflaton predominantly decays into the bosons and not the fermions. Difference in the Fermi-Bose occupation numbers results in the large gauge-mediated soft masses, which determine the post-inflationary evolution of the flat directions, suggesting that nonthermal phase transitions mediated by gauge messengers may play a crucial role in the Affelck-Dine mechanism for the generation of the baryon asymmetry.