The University of Southampton
University of Southampton Institutional Repository

Interplay between neutrino and gravity portals for FIMP dark matter

Interplay between neutrino and gravity portals for FIMP dark matter
Interplay between neutrino and gravity portals for FIMP dark matter
In the classic type I seesaw mechanism with very heavy right-handed (RH) neutrinos, it is possible to account for dark matter via RH neutrino portal couplings to a feebly interacting massive particle (FIMP) dark sector. However, for large RH neutrino masses, gravity can play an important role. We study the interplay between the neutrino portal through the right-handed neutrinos and the gravity portal through the massless spin-2 graviton in producing dark matter particles in the early universe. As a concrete example, we consider the minimal and realistic Littlest Seesaw model with two RH neutrinos, augmented with a dark scalar and a dark fermion charged under a global $U(1)_D$ dark symmetry. In the model, the usual seesaw neutrino Yukawa couplings and the right-handed neutrino masses (the lightest being about $5\times 10^{10}$ GeV) are fixed by neutrino oscillations data and leptogenesis. Hence, we explore the parameter space of the two RH neutrino portal couplings, the two dark particle masses and the reheating temperature of the universe, where the correct dark matter relic abundance is achieved through the freeze-in mechanism. In particular, we highlight which class of processes dominate the dark matter production. We find that, despite the presence of the gravity portal, the dark matter production relies on the usual seesaw neutrino Yukawa coupling in some regions of the parameter space, so realising a direct link between dark matter and neutrino phenomenology. Finally, we report the threshold values for the neutrino portal couplings below which the neutrino portal is irrelevant and the Planckian Interacting Dark Matter paradigm is preserved.
hep-ph
Chianese, Marco
73113e4b-5eb5-4cdc-831b-90f4678588d6
Fu, Bowen
71c18b27-d30a-4e33-806b-e45ea5446e46
King, Stephen F.
f8c616b7-0336-4046-a943-700af83a1538
Chianese, Marco
73113e4b-5eb5-4cdc-831b-90f4678588d6
Fu, Bowen
71c18b27-d30a-4e33-806b-e45ea5446e46
King, Stephen F.
f8c616b7-0336-4046-a943-700af83a1538

Chianese, Marco, Fu, Bowen and King, Stephen F. (2021) Interplay between neutrino and gravity portals for FIMP dark matter. JCAP, 2021 (1), [034]. (doi:10.1088/1475-7516/2021/01/034).

Record type: Article

Abstract

In the classic type I seesaw mechanism with very heavy right-handed (RH) neutrinos, it is possible to account for dark matter via RH neutrino portal couplings to a feebly interacting massive particle (FIMP) dark sector. However, for large RH neutrino masses, gravity can play an important role. We study the interplay between the neutrino portal through the right-handed neutrinos and the gravity portal through the massless spin-2 graviton in producing dark matter particles in the early universe. As a concrete example, we consider the minimal and realistic Littlest Seesaw model with two RH neutrinos, augmented with a dark scalar and a dark fermion charged under a global $U(1)_D$ dark symmetry. In the model, the usual seesaw neutrino Yukawa couplings and the right-handed neutrino masses (the lightest being about $5\times 10^{10}$ GeV) are fixed by neutrino oscillations data and leptogenesis. Hence, we explore the parameter space of the two RH neutrino portal couplings, the two dark particle masses and the reheating temperature of the universe, where the correct dark matter relic abundance is achieved through the freeze-in mechanism. In particular, we highlight which class of processes dominate the dark matter production. We find that, despite the presence of the gravity portal, the dark matter production relies on the usual seesaw neutrino Yukawa coupling in some regions of the parameter space, so realising a direct link between dark matter and neutrino phenomenology. Finally, we report the threshold values for the neutrino portal couplings below which the neutrino portal is irrelevant and the Planckian Interacting Dark Matter paradigm is preserved.

Text
2009.01847v2 - Accepted Manuscript
Restricted to Repository staff only until 20 January 2022.
Request a copy

More information

Submitted date: 15 September 2020
Accepted/In Press date: 26 October 2020
Published date: 20 January 2021
Additional Information: 19 pages, 7 figures. v2: version published in JCAP
Keywords: hep-ph

Identifiers

Local EPrints ID: 447365
URI: http://eprints.soton.ac.uk/id/eprint/447365
PURE UUID: 80c7a25d-21fb-4dfe-b9cd-6ef9ae836d71

Catalogue record

Date deposited: 10 Mar 2021 17:35
Last modified: 10 Mar 2021 17:40

Export record

Altmetrics

Contributors

Author: Marco Chianese
Author: Bowen Fu
Author: Stephen F. King

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×