Expected LHAASO sensitivity to decaying dark matter signatures from dwarf galaxies gamma-ray emission

TL;DR

This paper forecasts LHAASO's sensitivity to gamma-ray signals from decaying dark matter in dwarf galaxies, highlighting its potential to probe heavy dark matter particles with high precision.

Contribution

It provides the first detailed sensitivity forecast of LHAASO for detecting gamma-ray signatures from decaying dark matter in dwarf galaxies, including uncertainties.

Findings

LHAASO can detect decaying DM particles above 1 TeV.

Sensitivity to DM decay lifetime ranges from 10^{26} to 10^{28} seconds.

Combined analysis of 19 dwarf galaxies enhances detection prospects.

Abstract

As a next-generation complex extensive air shower array with a large field of view, the large high altitude air shower observatory (LHAASO) is very sensitive to the very high energy gamma-rays from $\sim$ 300 GeV to 1 PeV, and may thus serve as an important probe for the heavy dark matter (DM) particles. In this study, we make a forecast for the LHAASO sensitivities to the gamma-ray signatures resulting from DM decay in dwarf spheroidal satellite galaxies (dSphs) within the LHAASO field of view. Both individual and combined limits for 19 dSphs incorporating the uncertainties of the DM density profile are explored. Owing to the large effective area and strong capability of the photon-proton discrimination, we find that LHASSSO is sensitive to the signatures from decaying DM particles above $\mathcal{O}(1)$ TeV. The LHAASO sensitivity to the DM decay lifetime reaches $\mathcal{O} (10^{26}) \sim \mathcal{O} (10^{28})$ s for several decay channels at the DM mass scale from 1 TeV to 100 TeV.