Gravitino Dark Matter and Light Gluino in an R-invariant Low Scale Gauge Mediation

TL;DR

This paper explores a model where gravitinos serve as warm dark matter due to entropy production, and demonstrates that gluinos can be lighter than winos while maintaining GUT relations.

Contribution

It introduces a simple R-invariant gauge mediation model with keV gravitino mass and discusses the possibility of lighter gluinos than winos under GUT constraints.

Findings

Gravitino acts as warm dark matter due to entropy production.

Gluino can be lighter than wino while satisfying GUT relations.

Model supports keV-range gravitino as dark matter candidate.

Abstract

We consider the simplest class of the R-invariant gauge mediation model with the gravitino mass in the one to ten keV range. We show that the entropy production from the supersymmetry breaking sector makes the gravitino into a warm dark matter candidate. We also discuss that the gluino mass can be lighter than the wino mass even when the messenger sector satisfies the GUT relations at the GUT scale.