Theory HEP Seminar

Shedding New Light on Sterile Neutrinos

Brian Shuve

Perimeter Institute

Theories with sterile neutrinos are well-motivated extensions to the Standard Model that can account for the observed dark matter abundance, the baryon-antibaryon asymmetry and neutrino masses. The recent detection of a possible X-ray line “smoking gun” of sterile neutrino dark matter decay gives further impetus to their study. I give an overview of the physical mechanisms responsible for dark matter production and the baryon asymmetry with sub-weak-scale sterile neutrinos, showing that substantial tuning/alignment of model parameters is necessary for the minimal model to correctly account for either phenomenon. Motivated by this observation, I show how new interactions coupled to Standard Model fields can substantially enhance the baryon asymmetry and dark matter abundances, obviating the need for any tuning among model parameters, and providing new experimental probes to shed light on sterile neutrino cosmology.