Sterile Neutrino Dark Matter Production in the Neutrino-phillic Two Higgs Doublet Model

Abstract

Sterile Neutrinos with a mass in the keV range form a good candidate for dark matter. They are naturally produced from neutrino oscillations via their mixing with the active neutrinos. However the production via non-resonant neutrino oscillations has recently been ruled out. The alternative production via Higgs decay is negligibly small compared to neutrino oscillations. We show that in the neutrino-phillic two Higgs doublet model, the contribution from Higgs decay can dominate over the contribution from neutrino oscillations and evade all constraints. We also study the free-streaming horizon and find that a sterile neutrino mass in the range of 4 to 53 keV leads to warm dark matter.

Comments: 20 pages, 3 figures; v2: references added, Pauli blocking included, leading to about 40% correction to DM abundance, freestreaming horizon unaffected, conclusions unchanged, published in JHEP