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Completing RHINO

Completing RHINO
Completing RHINO
The right-handed (RH) Higgs-induced neutrino mixing (RHINO) model explains neutrino masses and origin of matter in the universe within a unified picture. The mixing, effectively described by a dimension five operator, is responsible both for the production 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 from Higgs portal interactions, their abundance can thermalise prior to the onset of source-dark neutrino oscillations, resulting into an enhanced production of dark neutrinos that thus can play the role of decaying dark matter (DM) for a much higher seesaw scale. This can be above the sphaleron freeze-out temperature and as high as $\sim 100\,{\rm TeV}$, so that strong thermal resonant leptogenesis for the generation of the matter-antimatter asymmetry is viable. We obtain a $\sim 1\,{\rm TeV}$--$1\,{\rm PeV}$ allowed dark neutrino mass range. Intriguingly, their decays can also explain a neutrino flux excess at ${\cal O}(100\,{\rm TeV})$ energies recently confirmed by the IceCube collaboration analysing 7.5yr HESE data. Our results also point to an effective scale for Higgs portal interactions nicely identifiable with the grandunified scale and many orders of magnitude below the effective scale for the mixing. We explain this hierarchy in a UV-complete model with a very heavy fermion as mediator: the first scale corresponds to the fundamental scale of new physics, while the second is much higher because of a very small coupling identifiable with a symmetry breaking parameter. Therefore, RHINO realises a simple unified model of neutrino masses and origin of matter in the universe currently under scrutiny at neutrino telescopes and potentially embeddable within a grandunified model.
hep-ph, astro-ph.CO, astro-ph.HE
Bari, Pasquale Di
3fe21e59-0eff-41bc-8faa-fdd817146418
Murphy, Adam
02b9d571-3ac2-4e55-8bbf-e7d190e816a1
Bari, Pasquale Di
3fe21e59-0eff-41bc-8faa-fdd817146418
Murphy, Adam
02b9d571-3ac2-4e55-8bbf-e7d190e816a1

[Unknown type: UNSPECIFIED]

Record type: UNSPECIFIED

Abstract

The right-handed (RH) Higgs-induced neutrino mixing (RHINO) model explains neutrino masses and origin of matter in the universe within a unified picture. The mixing, effectively described by a dimension five operator, is responsible both for the production 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 from Higgs portal interactions, their abundance can thermalise prior to the onset of source-dark neutrino oscillations, resulting into an enhanced production of dark neutrinos that thus can play the role of decaying dark matter (DM) for a much higher seesaw scale. This can be above the sphaleron freeze-out temperature and as high as $\sim 100\,{\rm TeV}$, so that strong thermal resonant leptogenesis for the generation of the matter-antimatter asymmetry is viable. We obtain a $\sim 1\,{\rm TeV}$--$1\,{\rm PeV}$ allowed dark neutrino mass range. Intriguingly, their decays can also explain a neutrino flux excess at ${\cal O}(100\,{\rm TeV})$ energies recently confirmed by the IceCube collaboration analysing 7.5yr HESE data. Our results also point to an effective scale for Higgs portal interactions nicely identifiable with the grandunified scale and many orders of magnitude below the effective scale for the mixing. We explain this hierarchy in a UV-complete model with a very heavy fermion as mediator: the first scale corresponds to the fundamental scale of new physics, while the second is much higher because of a very small coupling identifiable with a symmetry breaking parameter. Therefore, RHINO realises a simple unified model of neutrino masses and origin of matter in the universe currently under scrutiny at neutrino telescopes and potentially embeddable within a grandunified model.

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2210.10801v1 - Author's Original
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Accepted/In Press date: 19 October 2022
Additional Information: 28 pages, 10 figures
Keywords: hep-ph, astro-ph.CO, astro-ph.HE

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Local EPrints ID: 472301
URI: http://eprints.soton.ac.uk/id/eprint/472301
PURE UUID: 54c7ed3d-0b73-4ad4-a79e-ce2755589ec9

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Date deposited: 30 Nov 2022 18:01
Last modified: 30 Nov 2022 18:01

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Author: Adam Murphy

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