Constraints on Heavy Decaying Dark Matter from 570 Days of LHAASO Observations

The kilometer square array (KM2A) of the large high altitude air shower observatory (LHAASO) aims at surveying the northern.-ray sky at energies above 10 TeV with unprecedented sensitivity. gamma-ray observations have long been one of the most powerful tools for dark matter searches, as, e.g., high-energy gamma rays could be produced by the decays of heavy dark matter particles. In this Letter, we present the first dark matter analysis with LHAASO-KM2A, using the first 340 days of data from 1/2-KM2A and 230 days of data from 3/4-KM2A. Several regions of interest are used to search for a signal and account for the residual cosmic-ray background after gamma/hadron separation. We find no excess of dark matter signals, and thus place some of the strongest gamma-ray constraints on the lifetime of heavy dark matter particles with mass between 105 and 109 GeV. Our results with LHAASO are robust, and have important implications for dark matter interpretations of the diffuse astrophysical high-energy neutrino emission.

Automated summary

In this study, the kilometer square array (KM2A) of the large high altitude air shower observatory (LHAASO) was used to analyze dark matter by searching for signals at energies above 10 TeV. The results showed no excess of dark matter signals and placed strong constraints on the lifetime of heavy dark matter particles. These findings have important implications for dark matter interpretations of the diffuse astrophysical high-energy neutrino emission.