Flavoured leptogenesis and CP μτ symmetry
Abstract We present a systematic study of leptogenesis in neutrino mass models with μτ-flavoured CP symmetry. In addition to the strong hierarchical N1-dominated scenario (N 1DS) in the ‘two flavour regime’ of leptogenesis, we show that one may choose the right-handed (RH) neutrino mass hierarchy as...
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| Format: | Article |
| Language: | English |
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SpringerOpen
2020-01-01
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| Series: | Journal of High Energy Physics |
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| Online Access: | https://doi.org/10.1007/JHEP01(2020)193 |
| _version_ | 1818460970832363520 |
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| author | Rome Samanta Manibrata Sen |
| author_facet | Rome Samanta Manibrata Sen |
| author_sort | Rome Samanta |
| collection | DOAJ |
| description | Abstract We present a systematic study of leptogenesis in neutrino mass models with μτ-flavoured CP symmetry. In addition to the strong hierarchical N1-dominated scenario (N 1DS) in the ‘two flavour regime’ of leptogenesis, we show that one may choose the right-handed (RH) neutrino mass hierarchy as mild as M 2 ≃ 4.7M 1 for a perfectly valid hierarchical N 1DS. This reduces the lower bound on the allowed values of M 1, compared to what is stated in the literature. The consideration of flavour effects due to the heavy neutrinos also translate into an upper bound on M 1. It is only below this bound that the observed baryon-to-photon ratio can be realized for a standard N 1 domination, else a substantial part of the parameter space is also compatible with N 2DS. We deduce conditions under which the baryon asymmetry produced by the second RH neutrino plays an important role. Finally, we discuss another scenario where lepton asymmetry generated by N 2 in the two flavour regime faces washout by N 1 in the three flavour regime. Considering a hierarchical light neutrino mass spectrum, which is now favoured by cosmological observations, we show that at the end of N 1-leptogenesis, the asymmetry generated by N 2 survives only in the electron flavour and about 33% of the parameter space is consistent with a pure N 2-leptogenesis. |
| first_indexed | 2024-12-14T23:38:43Z |
| format | Article |
| id | doaj.art-44d62d411c7944b2b4b0fc45e27ec008 |
| institution | Directory Open Access Journal |
| issn | 1029-8479 |
| language | English |
| last_indexed | 2024-12-14T23:38:43Z |
| publishDate | 2020-01-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | Journal of High Energy Physics |
| spelling | doaj.art-44d62d411c7944b2b4b0fc45e27ec0082022-12-21T22:43:34ZengSpringerOpenJournal of High Energy Physics1029-84792020-01-012020113410.1007/JHEP01(2020)193Flavoured leptogenesis and CP μτ symmetryRome Samanta0Manibrata Sen1Physics and Astronomy, University of SouthamptonDepartment of Physics, University of California BerkeleyAbstract We present a systematic study of leptogenesis in neutrino mass models with μτ-flavoured CP symmetry. In addition to the strong hierarchical N1-dominated scenario (N 1DS) in the ‘two flavour regime’ of leptogenesis, we show that one may choose the right-handed (RH) neutrino mass hierarchy as mild as M 2 ≃ 4.7M 1 for a perfectly valid hierarchical N 1DS. This reduces the lower bound on the allowed values of M 1, compared to what is stated in the literature. The consideration of flavour effects due to the heavy neutrinos also translate into an upper bound on M 1. It is only below this bound that the observed baryon-to-photon ratio can be realized for a standard N 1 domination, else a substantial part of the parameter space is also compatible with N 2DS. We deduce conditions under which the baryon asymmetry produced by the second RH neutrino plays an important role. Finally, we discuss another scenario where lepton asymmetry generated by N 2 in the two flavour regime faces washout by N 1 in the three flavour regime. Considering a hierarchical light neutrino mass spectrum, which is now favoured by cosmological observations, we show that at the end of N 1-leptogenesis, the asymmetry generated by N 2 survives only in the electron flavour and about 33% of the parameter space is consistent with a pure N 2-leptogenesis.https://doi.org/10.1007/JHEP01(2020)193Cosmology of Theories beyond the SMCP violationNeutrino Physics |
| spellingShingle | Rome Samanta Manibrata Sen Flavoured leptogenesis and CP μτ symmetry Journal of High Energy Physics Cosmology of Theories beyond the SM CP violation Neutrino Physics |
| title | Flavoured leptogenesis and CP μτ symmetry |
| title_full | Flavoured leptogenesis and CP μτ symmetry |
| title_fullStr | Flavoured leptogenesis and CP μτ symmetry |
| title_full_unstemmed | Flavoured leptogenesis and CP μτ symmetry |
| title_short | Flavoured leptogenesis and CP μτ symmetry |
| title_sort | flavoured leptogenesis and cp μτ symmetry |
| topic | Cosmology of Theories beyond the SM CP violation Neutrino Physics |
| url | https://doi.org/10.1007/JHEP01(2020)193 |
| work_keys_str_mv | AT romesamanta flavouredleptogenesisandcpmtsymmetry AT manibratasen flavouredleptogenesisandcpmtsymmetry |