The University of Southampton
University of Southampton Institutional Repository
Warning ePrints Soton is experiencing an issue with some file downloads not being available. We are working hard to fix this. Please bear with us.

Strong thermal leptogenesis and the absolute neutrino mass scale

Strong thermal leptogenesis and the absolute neutrino mass scale
Strong thermal leptogenesis and the absolute neutrino mass scale
We show that successful strong thermal leptogenesis, where the final asymmetry is independent of the initial conditions and in particular a large pre-existing asymmetry is efficiently washed-out, favours values of the lightest neutrino mass m1gtrsim10 meV for normal ordering (NO) and m1gtrsim3 meV for inverted ordering (IO) for models with orthogonal matrix entries respecting |?ij2|lesssim2. We show analytically why lower values of m1 require a higher level of fine tuning in the seesaw formula and/or in the flavoured decay parameters (in the electronic for NO, in the muonic for IO). We also show how this constraint exists thanks to the measured values of the neutrino mixing angles and could be tightened by a future determination of the Dirac phase. Our analysis also allows us to place a more stringent constraint for a specific model or class of models, such as SO(10)-inspired models, and shows that some models cannot realise strong thermal leptogenesis for any value of m1. A scatter plot analysis fully supports the analytical results. We also briefly discuss the interplay with absolute neutrino mass scale experiments concluding that they will be able in the coming years to either corner strong thermal leptogenesis or find positive signals pointing to a non-vanishing m1. Since the constraint is much stronger for NO than for IO, it is very important that new data from planned neutrino oscillation experiments will be able to solve the ambiguity.
leptogenesis, neutrino masses from cosmology
1475-7516
50
Bari, Pasquale Di
3fe21e59-0eff-41bc-8faa-fdd817146418
King, Sophie E.
839d9ee7-1da6-42b6-8c23-02e051a1fb7d
Fiorentin, Michele Re
14592110-0cef-42b7-b620-26ce94a1e063
Bari, Pasquale Di
3fe21e59-0eff-41bc-8faa-fdd817146418
King, Sophie E.
839d9ee7-1da6-42b6-8c23-02e051a1fb7d
Fiorentin, Michele Re
14592110-0cef-42b7-b620-26ce94a1e063

Bari, Pasquale Di, King, Sophie E. and Fiorentin, Michele Re (2014) Strong thermal leptogenesis and the absolute neutrino mass scale. Journal of Cosmology and Astroparticle Physics, 2014 (3), 50. (doi:10.1088/1475-7516/2014/03/050).

Record type: Article

Abstract

We show that successful strong thermal leptogenesis, where the final asymmetry is independent of the initial conditions and in particular a large pre-existing asymmetry is efficiently washed-out, favours values of the lightest neutrino mass m1gtrsim10 meV for normal ordering (NO) and m1gtrsim3 meV for inverted ordering (IO) for models with orthogonal matrix entries respecting |?ij2|lesssim2. We show analytically why lower values of m1 require a higher level of fine tuning in the seesaw formula and/or in the flavoured decay parameters (in the electronic for NO, in the muonic for IO). We also show how this constraint exists thanks to the measured values of the neutrino mixing angles and could be tightened by a future determination of the Dirac phase. Our analysis also allows us to place a more stringent constraint for a specific model or class of models, such as SO(10)-inspired models, and shows that some models cannot realise strong thermal leptogenesis for any value of m1. A scatter plot analysis fully supports the analytical results. We also briefly discuss the interplay with absolute neutrino mass scale experiments concluding that they will be able in the coming years to either corner strong thermal leptogenesis or find positive signals pointing to a non-vanishing m1. Since the constraint is much stronger for NO than for IO, it is very important that new data from planned neutrino oscillation experiments will be able to solve the ambiguity.

Text
1475-7516_2014_03_050.pdf - Version of Record
Available under License Other.
Download (4MB)

More information

Published date: March 2014
Keywords: leptogenesis, neutrino masses from cosmology
Organisations: Physics & Astronomy

Identifiers

Local EPrints ID: 369355
URI: http://eprints.soton.ac.uk/id/eprint/369355
ISSN: 1475-7516
PURE UUID: 34714882-2136-4b1a-ac06-71a68b280849

Catalogue record

Date deposited: 24 Sep 2014 11:28
Last modified: 20 Nov 2021 18:37

Export record

Altmetrics

Contributors

Author: Sophie E. King
Author: Michele Re Fiorentin

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.

×