Improving HAWC dark matter constraints with inverse-Compton emission

The particle nature of dark matter (DM) has been a long-lasting mystery. Many models suggest that DM could decay or self annihilate into standard model particles, and thus could be a source of gamma rays in the sky. The High Altitude Water Cherenkov (HAWC) observatory has yielded some of the strongest limits in searches of DM decay or annihilation. Building on the flux limits provided by the HAWC collaboration in 2018, we consider the effects of additional components from Galactic secondary inverse-Compton scatterings and extragalactic DM distributions. We find that these effects can significantly improve the DM constraints, around a factor of few in some cases. This highlights the importance of considering secondary contributions in detail in LHAASO-WCDA and SWGO in the future.