Gravitino and Polonyi production in supergravity

TL;DR

This paper explores the production of gravitino and Polonyi particles during inflation in a supergravity model, showing their potential as dark matter candidates while avoiding common cosmological problems.

Contribution

It introduces a supergravity model with a non-minimal vector supermultiplet that naturally produces gravitinos and Polonyi particles during inflation, aligning with dark matter constraints.

Findings

Efficient production of gravitinos and Polonyi particles during inflation.

Post-inflation decay processes produce gravitinos consistent with dark matter.

The model avoids gravitino and Polonyi problems related to BBN and overproduction.

Abstract

We study production of gravitino and Polonyi particles in the minimal Starobinsky-Polonyi $\mathcal{N}=1$ supergravity with inflaton belonging to a massive vector supermultiplet. Our model has only one free parameter given by the scale of spontaneous SUSY breaking triggered by Polonyi chiral superfield. The vector supermultiplet generically enters the action non-minimally, via an arbitrary real function. This functon is chosen to generate the inflaton scalar potential of the Starobinsky model. Our supergravity model can be reformulated as an abelian supersymmetric gauge theory with the vector gauge superfield coupled to two (Higgs and Polonyi) chiral superfields interacting with supergravity, where the $U(1)$ gauge symmetry is spontaneously broken. We find that Polonyi and gravitino particles are efficiently produced during inflation. After inflation, perturbative decay of inflaton also produces Polonyi particles that rapidly decay into gravitinos. As a result, a coherent picture of inflation and dark matter emerges, where the abundance of produced gravitinos after inflation fits the CMB constraints as a Super Heavy Dark Matter (SHDM) candidate. Our scenario avoids the notorous gravitino and Polonyi problems with the Big Bang Nucleosynthesis (BBN) and DM overproduction.