Preheating in Supersymmetric Hybrid Inflation

TL;DR

This paper investigates preheating dynamics in supersymmetric hybrid inflation models, highlighting the effects of mixing and backreaction on particle production, especially axions, and demonstrating the model's consistency with experimental bounds.

Contribution

It provides a detailed analysis of preheating in supersymmetric hybrid inflation, emphasizing mixing effects and backreaction, and explores axion production suppression within a realistic model.

Findings

Preheating efficiently produces particles associated with homogeneous fields.

Mixing effects can significantly alter particle production rates.

Backreaction effects can suppress axion production, ensuring experimental safety.

Abstract

We study preheating in a general class of supersymmetric hybrid inflation model. Supersymmetry leads to only one coupling constant in the potential and thus only one natural frequency of oscillation for the homogeneous fields, whose classical evolution consequently differs from that of a general (non-supersymmetric) hybrid model. We emphasise the importance of mixing effects in these models which can significantly change the rate of production of particles. We perform a general study of the rate of production of the particles associated with the homogeneous fields, and show how preheating is efficient in producing these quanta. Preheating of other particle species will be model dependent, and in order to investigate this we consider a realistic working model of supersymmetric hybrid inflation which solves the strong-CP problem via an approximate Peccei-Quinn symmetry, which was proposed by us previously. We study axion production in this model and show that properly taking into account the mixing between the fields suppresses the axion production, yet enhances the production of other particles. Finally we demonstrate the importance of backreaction effects in this model which have the effect of shutting off axion production, leaving the axion safely within experimental bounds.