Gamma-ray detection from gravitino dark matter decay in the $\mu\nu$SSM

TL;DR

This paper investigates gamma-ray signals from gravitino dark matter decay within the $ u$SSM, assessing detectability by FERMI and constraining the model based on diffuse photon background measurements.

Contribution

It analyzes the gamma-ray signatures of gravitino dark matter in the $ u$SSM and evaluates the potential for detection with current gamma-ray observations.

Findings

Gravitino masses above 20 GeV are disfavored by diffuse photon background.

A 0.1-20 GeV gravitino mass range could produce detectable signals by FERMI.

Certain parameter regions of the $ u$SSM are testable with gamma-ray data.

Abstract

The $\mu\nu$SSM provides a solution to the $\mu$-problem of the MSSM and explains the origin of neutrino masses by simply using right-handed neutrino superfields. Given that R-parity is broken in this model, the gravitino is a natural candidate for dark matter since its lifetime becomes much longer than the age of the Universe. We consider the implications of gravitino dark matter in the $\mu\nu$SSM, analyzing in particular the prospects for detecting gamma rays from decaying gravitinos. If the gravitino explains the whole dark matter component, a gravitino mass larger than 20 GeV is disfavored by the isotropic diffuse photon background measurements. On the other hand, a gravitino with a mass range between 0.1-20 GeV gives rise to a signal that might be observed by the FERMI satellite. In this way important regions of the parameter space of the $\mu\nu$SSM can be checked.