Completing RHINO

doi:10.1007/JHEP03(2023)063

2023-03-09

Pasquale Di Bari *

Adam Murphy

DOI：10.1007/JHEP03(2023)063

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摘要

En 中文

The right-handed (RH) Higgs-induced neutrino mixing (RHINO) model ex-plains neutrino masses and origin of matter in the universe within a unified picture. Themixing, effectively described by a dimension five operator, is responsible both for the pro-duction of dark neutrinos, converting a small fraction of seesaw neutrinos acting as source,and for their decays. We show that including the production of source neutrinos fromHiggs portal interactions, their abundance can thermalise prior to the onset of source-darkneutrino oscillations, resulting into an enhanced production of dark neutrinos that thuscan play the role of decaying dark matter (DM) for a much higher seesaw scale. This canbe above the sphaleron freeze-out temperature and as high as similar to 100 TeV, so that strongthermal resonant leptogenesis for the generation of the matter-antimatter asymmetry isviable. We obtain a similar to 1 TeV-1 PeVallowed dark neutrino mass range. Intriguingly, theirdecays can also explain a neutrino flux excess atO(100 TeV)energies recently confirmedby the IceCube collaboration analysing 7.5 yr HESE data. Our results also point to aneffective scale for Higgs portal interactions nicely identifiable with the grandunified scaleand many orders of magnitude below the effective scale for the mixing. We explain thishierarchy in a UV-complete model with a very heavy fermion as mediator: the first scalecorresponds to the fundamental scale of new physics, while the second is much higher be-cause of a very small coupling that can be identified with a symmetry breaking parameter.Therefore, RHINO realises a simple unified model of neutrino masses and origin of matterin the universe currently under scrutiny at neutrino telescopes and potentially embeddablewithin a grandunified model.

Keyword:

Models for Dark Matter

Baryo-and Leptogenesis

Early Universe Particle Physics

Sterile or Heavy Neutrinos