Monochromatic neutrinos from dark matter through the Higgs portal

Abstract

AbstractWe define a minimal model of dark matter with a fermion singletχcoupled to the visible sector through the Higgs portal and with a heavy Dirac neutrinoNthat opens the annihilation channelχχ → Nν. The model provides the observed relic abundance consistently with bounds from direct searches and implies a monochromatic neutrino signal at 10 GeV–1 TeV in indirect searches. In particular, we obtain the capture rate ofχby the Sun and show that the signal could be above theneutrino floorproduced by cosmic rays showering in the solar surface. In most benchmark models this solar astrophysical background is above the expected dark matter signal, so the model that we propose is a canonical example of WIMP not excluded by direct searches that could be studied at neutrino telescopes and also at colliders.