Signatures of Neutrinophilic Pion Dark Matter

Abstract

We study the phenomenology of pion dark matter coupled to neutrinos in a confining sector that dynamically generates both small neutrino masses and dark matter mass from gauge confinement. Dark matter semi-annihilation to active neutrinos or annihilation to light sterile neutrinos can reproduce the observed relic abundance through thermal freeze-out while satisfying constraints from self-interactions. In the first scenario, semi-annihilations of sub-GeV dark matter in the galactic halo produce a flux of antineutrinos which can provide a viable interpretation for the mild electron antineutrino excess reported by the Super-Kamiokande collaboration. We assess the potential of the JUNO detector to test this interpretation. In the second scenario, light sterile neutrinos can leave signatures through displaced vertex searches at accelerator facilities.