Photon and neutrino fluxes from spheroidal dwarf galaxies in a decaying DM model

TL;DR

This paper explores a decaying dark matter model involving a scalar singlet that produces detectable gamma-ray and neutrino signals in dwarf galaxies, with potential observability in current experiments.

Contribution

It introduces a specific decaying dark matter scenario with detailed flux predictions for gamma rays and neutrinos, considering multiple astrophysical targets and parameter choices.

Findings

Predicted signals could be observable in certain parameter regions.

Flux calculations include Milky Way and 14 dwarf spheroidal galaxies.

Results depend on benchmark masses and coupling values within cosmological constraints.

Abstract

In this work, we investigate a decaying dark matter scenario and its associated indirect detection signatures. The model consists of a scalar singlet with a lifetime exceeding the age of the Universe. Stability is ensured by a $Z_2$ symmetry imposed on the Lagrangian, allowing decay through a non-minimal gravitational coupling. The decay of dark matter produces Standard Model particles, which subsequently yield products such as gamma rays, neutrinos, and charged particles. We computed the gamma-ray and neutrino fluxes generated by this candidate in the Milky Way and in 14 dwarf spheroidal galaxies, as well as the corresponding expected number of events in selected experiments, using dedicated numerical tools. Results are presented for three benchmark masses and three coupling values consistent with cosmological constraints, showing that the predicted signals can be observable in specific regions of parameter space.