Flavour and dark matter in a scoto/type-II seesaw model
Abstract The neutrino mass and dark matter (DM) problems are addressed in a Standard Model extension where the type-II seesaw and scotogenic mechanisms coexist. The model features a flavour 𝒵8 discrete symmetry which is broken down to a 𝒵2, stabilising the (scalar or fermion) DM particle. Spontaneou...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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SpringerOpen
2022-08-01
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| Series: | Journal of High Energy Physics |
| Subjects: | |
| Online Access: | https://doi.org/10.1007/JHEP08(2022)030 |
| _version_ | 1828325153650507776 |
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| author | D. M. Barreiros H. B. Câmara F. R. Joaquim |
| author_facet | D. M. Barreiros H. B. Câmara F. R. Joaquim |
| author_sort | D. M. Barreiros |
| collection | DOAJ |
| description | Abstract The neutrino mass and dark matter (DM) problems are addressed in a Standard Model extension where the type-II seesaw and scotogenic mechanisms coexist. The model features a flavour 𝒵8 discrete symmetry which is broken down to a 𝒵2, stabilising the (scalar or fermion) DM particle. Spontaneous CP violation is implemented through the complex vacuum expectation value of a singlet scalar field, inducing observable CP-violating effects in the lepton sector. The structure of the effective neutrino mass matrix leads to constraints on the low-energy neutrino observables, namely the atmospheric neutrino mixing angle θ 23, the Dirac CP-violating phase δ and the absolute neutrino mass scale m lightest. In particular, in most cases, the model selects one θ 23 octant with δ ≃ 3π/2. Moreover, the obtained lower bounds on m lightest are typically in the range probed by cosmology. We also analyse the constraints imposed on the model by current experimental limits on charged lepton flavour violating (cLFV) processes, as well as future projected sensitivities. It is shown that the Higgs triplet and scotogenic contributions to cLFV never overlap and that the interplay among Yukawa couplings, dark charged scalar masses and mixing leads to a wide parameter-space region compatible with current experimental bounds. We investigate the scalar and fermion DM parameter space of our model by considering relic density, direct-detection (DD) and collider constraints. For scalar DM the mass interval 68 GeV ≲ m DM ≲ 90 GeV is viable and will be probed by future DD searches. In the fermion DM case, correct relic density is always obtained for m DM ≳ 45 GeV thanks to dark fermion-scalar coannihilation channels. |
| first_indexed | 2024-04-13T19:18:16Z |
| format | Article |
| id | doaj.art-b0a56e5752324bdbb9ba1cf64cac5f99 |
| institution | Directory Open Access Journal |
| issn | 1029-8479 |
| language | English |
| last_indexed | 2024-04-13T19:18:16Z |
| publishDate | 2022-08-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | Journal of High Energy Physics |
| spelling | doaj.art-b0a56e5752324bdbb9ba1cf64cac5f992022-12-22T02:33:37ZengSpringerOpenJournal of High Energy Physics1029-84792022-08-012022815010.1007/JHEP08(2022)030Flavour and dark matter in a scoto/type-II seesaw modelD. M. Barreiros0H. B. Câmara1F. R. Joaquim2Departamento de Física and CFTP, Instituto Superior Técnico, Universidade de LisboaDepartamento de Física and CFTP, Instituto Superior Técnico, Universidade de LisboaDepartamento de Física and CFTP, Instituto Superior Técnico, Universidade de LisboaAbstract The neutrino mass and dark matter (DM) problems are addressed in a Standard Model extension where the type-II seesaw and scotogenic mechanisms coexist. The model features a flavour 𝒵8 discrete symmetry which is broken down to a 𝒵2, stabilising the (scalar or fermion) DM particle. Spontaneous CP violation is implemented through the complex vacuum expectation value of a singlet scalar field, inducing observable CP-violating effects in the lepton sector. The structure of the effective neutrino mass matrix leads to constraints on the low-energy neutrino observables, namely the atmospheric neutrino mixing angle θ 23, the Dirac CP-violating phase δ and the absolute neutrino mass scale m lightest. In particular, in most cases, the model selects one θ 23 octant with δ ≃ 3π/2. Moreover, the obtained lower bounds on m lightest are typically in the range probed by cosmology. We also analyse the constraints imposed on the model by current experimental limits on charged lepton flavour violating (cLFV) processes, as well as future projected sensitivities. It is shown that the Higgs triplet and scotogenic contributions to cLFV never overlap and that the interplay among Yukawa couplings, dark charged scalar masses and mixing leads to a wide parameter-space region compatible with current experimental bounds. We investigate the scalar and fermion DM parameter space of our model by considering relic density, direct-detection (DD) and collider constraints. For scalar DM the mass interval 68 GeV ≲ m DM ≲ 90 GeV is viable and will be probed by future DD searches. In the fermion DM case, correct relic density is always obtained for m DM ≳ 45 GeV thanks to dark fermion-scalar coannihilation channels.https://doi.org/10.1007/JHEP08(2022)030Flavour SymmetriesLepton Flavour Violation (charged)Neutrino MixingParticle Nature of Dark Matter |
| spellingShingle | D. M. Barreiros H. B. Câmara F. R. Joaquim Flavour and dark matter in a scoto/type-II seesaw model Journal of High Energy Physics Flavour Symmetries Lepton Flavour Violation (charged) Neutrino Mixing Particle Nature of Dark Matter |
| title | Flavour and dark matter in a scoto/type-II seesaw model |
| title_full | Flavour and dark matter in a scoto/type-II seesaw model |
| title_fullStr | Flavour and dark matter in a scoto/type-II seesaw model |
| title_full_unstemmed | Flavour and dark matter in a scoto/type-II seesaw model |
| title_short | Flavour and dark matter in a scoto/type-II seesaw model |
| title_sort | flavour and dark matter in a scoto type ii seesaw model |
| topic | Flavour Symmetries Lepton Flavour Violation (charged) Neutrino Mixing Particle Nature of Dark Matter |
| url | https://doi.org/10.1007/JHEP08(2022)030 |
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