Dark matter interpretation of GRB 221009A: a singlet scalar explains LHAASO data

TL;DR

This paper proposes a dark matter model involving a singlet scalar that decays into high-energy photons, explaining the 18 TeV gamma-ray event observed by LHAASO from GRB 221009A.

Contribution

It introduces a novel dark matter decay mechanism involving a singlet scalar and cosmic ray up-scattering to explain high-energy gamma-ray observations.

Findings

A singlet scalar DM can produce high-energy gamma rays via di-photon decay.

The model accounts for the 18 TeV gamma-ray event detected by LHAASO.

Dark matter decay contributes to gamma-ray signals from GRBs.

Abstract

In this work, we find a new signal of dark matter (DM) through an intensive gamma ray burst (GRB), called GRB 221009A. This indirect detection approach devotes to the decay of DM particles into high energy (HE) photons. In this context, a singlet scalar DM generated at the redshift of the GRB is up-scattered by the high energy cosmic rays (HECRs) during its propagation to Earth. This highly boosted DM then possesses a high flux and undergoes a dominant di-photon decay before reaching the detector. The Large High Altitude Air Shower Observatory (LHAASO) probes such energetic gamma rays whereby has recorded a 18 TeV event for the aforementioned GRB.