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

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.