Model independent limits on an ultra-light gravitino from Supernovae

TL;DR

This paper revisits astrophysical constraints on ultra-light gravitinos, extending analysis to general models and R-parity breaking, and finds limited model-independent exclusions but more stringent limits under specific assumptions.

Contribution

It provides a comprehensive analysis of supernova constraints on ultra-light gravitinos, including general models and R-parity breaking, using both frequentist and Bayesian methods.

Findings

Small gravitino mass window can be excluded independently of models.

Model-dependent limits are more stringent than model-independent ones.

Bayesian analysis shows volume effects influencing constraints.

Abstract

We revisit astrophysical constraints on models with an ultra-light gravitino, in particular extending the analysis to more general models and the case of R-parity breaking. These constraints allow to restrict the value of the gravitino mass depending on the masses of scalar moduli. We perform both a frequentist and bayesian analysis and we find comparable results, even if the bayesian analysis is in part affected by volume effects. Only a small window of gravitino masses can be excluded by the SN constraints in a model-independent way, while limits obtained with a definite assumption on the scalar masses result more stringent.