The nonperturbative decay of SUSY flat directions

TL;DR

This paper investigates the nonperturbative decay mechanisms of supersymmetric flat directions during the post-inflationary epoch, revealing that they typically decay rapidly through exponential amplification of field excitations.

Contribution

It provides a detailed analysis of the decay process of SUSY flat directions due to D-term potentials, combining analytical and numerical methods to identify decay timescales.

Findings

Flat directions decay within their first few rotations for many parameters.

Exponential amplification of field excitations leads to rapid decay.

Decay affects reheating and thermalization after inflation.

Abstract

We compute the nonperturbative decay of supersymmetric flat directions due to their D-term potential. Flat directions can develop large vacuum expectation values (vevs) during inflation, and, if they are long-lived, this can strongly affect the reheating and thermalization stages after the inflation. We study a generic system of two U(1) or SU(2) flat directions which are cosmologically evolving after inflation. After proper gauge fixing, we show that the excitations of the fields around this background can undergo exponential amplification, at the expense of the energy density of the flat directions. We compute this effect for several values of the masses and the initial vevs of the two flat directions, through a combination of analytical methods and extensive numerical simulations. For a wide range of parameters the flat directions decay within their first few rotations.