Successful N{sub 2} leptogenesis with flavour coupling effects in realistic unified models
Abstract
In realistic unified models involving socalled SO(10)inspired patterns of Dirac and heavy righthanded (RH) neutrino masses, the lightest righthanded neutrino N{sub 1} is too light to yield successful thermal leptogenesis, barring highly fine tuned solutions, while the second heaviest righthanded neutrino N{sub 2} is typically in the correct mass range. We show that flavour coupling effects in the Boltzmann equations may be crucial to the success of such N{sub 2} dominated leptogenesis, by helping to ensure that the flavour asymmetries produced at the N{sub 2} scale survive N{sub 1} washout. To illustrate these effects we focus on N{sub 2} dominated leptogenesis in an existing model, the A to Z of flavour with PatiSalam, where the neutrino Dirac mass matrix may be equal to an uptype quark mass matrix and has a particular constrained structure. The numerical results, supported by analytical insight, show that in order to achieve successful N{sub 2} leptogenesis, consistent with neutrino phenomenology, requires a “flavour swap scenario” together with a less hierarchical pattern of RH neutrino masses than naively expected, at the expense of some mild finetuning. In the considered A to Z model neutrino masses are predicted to be normal ordered, with an atmospheric neutrino mixingmore »
 Authors:
 Department of Physics and Astronomy, University of Southampton,Highfield, Southampton SO17 1BJ (United Kingdom)
 Publication Date:
 Sponsoring Org.:
 SCOAP3, CERN, Geneva (Switzerland)
 OSTI Identifier:
 22458385
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2015; Journal Issue: 10; Other Information: PUBLISHERID: JCAP10(2015)008; OAI: oai:repo.scoap3.org:12107; Article funded by SCOAP3. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 License. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.; Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ASYMMETRY; BOLTZMANN EQUATION; FLAVOR MODEL; MASS; NEUTRINO MIXING ANGLE; NEUTRINO OSCILLATION; NEUTRINOS; PARTICLE PRODUCTION; U QUARKS; UNIFIED MODEL
Citation Formats
Bari, Pasquale Di, and King, Stephen F. Successful N{sub 2} leptogenesis with flavour coupling effects in realistic unified models. United States: N. p., 2015.
Web. doi:10.1088/14757516/2015/10/008.
Bari, Pasquale Di, & King, Stephen F. Successful N{sub 2} leptogenesis with flavour coupling effects in realistic unified models. United States. doi:10.1088/14757516/2015/10/008.
Bari, Pasquale Di, and King, Stephen F. 2015.
"Successful N{sub 2} leptogenesis with flavour coupling effects in realistic unified models". United States.
doi:10.1088/14757516/2015/10/008.
@article{osti_22458385,
title = {Successful N{sub 2} leptogenesis with flavour coupling effects in realistic unified models},
author = {Bari, Pasquale Di and King, Stephen F.},
abstractNote = {In realistic unified models involving socalled SO(10)inspired patterns of Dirac and heavy righthanded (RH) neutrino masses, the lightest righthanded neutrino N{sub 1} is too light to yield successful thermal leptogenesis, barring highly fine tuned solutions, while the second heaviest righthanded neutrino N{sub 2} is typically in the correct mass range. We show that flavour coupling effects in the Boltzmann equations may be crucial to the success of such N{sub 2} dominated leptogenesis, by helping to ensure that the flavour asymmetries produced at the N{sub 2} scale survive N{sub 1} washout. To illustrate these effects we focus on N{sub 2} dominated leptogenesis in an existing model, the A to Z of flavour with PatiSalam, where the neutrino Dirac mass matrix may be equal to an uptype quark mass matrix and has a particular constrained structure. The numerical results, supported by analytical insight, show that in order to achieve successful N{sub 2} leptogenesis, consistent with neutrino phenomenology, requires a “flavour swap scenario” together with a less hierarchical pattern of RH neutrino masses than naively expected, at the expense of some mild finetuning. In the considered A to Z model neutrino masses are predicted to be normal ordered, with an atmospheric neutrino mixing angle well into the second octant and the Dirac phase δ≃20{sup ∘}, a set of predictions that will be tested in the next years in neutrino oscillation experiments. Flavour coupling effects may be relevant for other SO(10)inspired unified models where N{sub 2} leptogenesis is necessary.},
doi = {10.1088/14757516/2015/10/008},
journal = {Journal of Cosmology and Astroparticle Physics},
number = 10,
volume = 2015,
place = {United States},
year = 2015,
month =
}

In realistic unified models involving socalled SO(10)inspired patterns of Dirac and heavy righthanded (RH) neutrino masses, the lightest righthanded neutrino N{sub 1} is too light to yield successful thermal leptogenesis, barring highly fine tuned solutions, while the second heaviest righthanded neutrino N{sub 2} is typically in the correct mass range. We show that flavour coupling effects in the Boltzmann equations may be crucial to the success of such N{sub 2} dominated leptogenesis, by helping to ensure that the flavour asymmetries produced at the N{sub 2} scale survive N{sub 1} washout. To illustrate these effects we focus on N{sub 2} dominatedmore »

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