The bearable compositeness of leptons
Abstract Partial compositeness as a theory of flavor in the lepton sector is assessed. We begin presenting the first systematic analysis of neutrino mass generation in this context, and identifying the distinctive mass textures. We then update the bounds from charged lepton flavor and CP violating o...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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SpringerOpen
2018-10-01
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| Series: | Journal of High Energy Physics |
| Subjects: | |
| Online Access: | http://link.springer.com/article/10.1007/JHEP10(2018)017 |
| _version_ | 1818317721211764736 |
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| author | Michele Frigerio Marco Nardecchia Javi Serra Luca Vecchi |
| author_facet | Michele Frigerio Marco Nardecchia Javi Serra Luca Vecchi |
| author_sort | Michele Frigerio |
| collection | DOAJ |
| description | Abstract Partial compositeness as a theory of flavor in the lepton sector is assessed. We begin presenting the first systematic analysis of neutrino mass generation in this context, and identifying the distinctive mass textures. We then update the bounds from charged lepton flavor and CP violating observables. We put forward a U(1)3 × CP symmetry of the composite sector, in order to allow the new physics to be not far above the TeV scale. This hypothesis effectively suppresses the new contributions to the electron EDM and μ → eγ, by far the most constraining observables, and results in a novel pattern of flavor violation and neutrino masses. The CP violation in the elementary-composite mixing is shown to induce a CKM phase of the correct size, as well as order-one phases in the PMNS matrix. We compare with the alternative possibility of introducing multiple scales of compositeness for leptons, that also allow to evade flavor and CP constraints. Finally, we examine violations of lepton flavor universality in B-meson semi-leptonic decays. The neutral-current anomalies can be accommodated, predicting strong correlations among different lepton flavors, with a few channels close to the experimental sensitivity. |
| first_indexed | 2024-12-13T09:41:49Z |
| format | Article |
| id | doaj.art-75cc28282cb3413988d4da912797ff2a |
| institution | Directory Open Access Journal |
| issn | 1029-8479 |
| language | English |
| last_indexed | 2024-12-13T09:41:49Z |
| publishDate | 2018-10-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | Journal of High Energy Physics |
| spelling | doaj.art-75cc28282cb3413988d4da912797ff2a2022-12-21T23:52:10ZengSpringerOpenJournal of High Energy Physics1029-84792018-10-0120181016010.1007/JHEP10(2018)017The bearable compositeness of leptonsMichele Frigerio0Marco Nardecchia1Javi Serra2Luca Vecchi3Laboratoire Charles Coulomb (L2C), University of Montpellier, CNRSDepartment of Theoretical Physics, CERNPhysik-Department, Technische Universität MünchenTheoretical Particle Physics Laboratory, Institute of Physics, EPFLAbstract Partial compositeness as a theory of flavor in the lepton sector is assessed. We begin presenting the first systematic analysis of neutrino mass generation in this context, and identifying the distinctive mass textures. We then update the bounds from charged lepton flavor and CP violating observables. We put forward a U(1)3 × CP symmetry of the composite sector, in order to allow the new physics to be not far above the TeV scale. This hypothesis effectively suppresses the new contributions to the electron EDM and μ → eγ, by far the most constraining observables, and results in a novel pattern of flavor violation and neutrino masses. The CP violation in the elementary-composite mixing is shown to induce a CKM phase of the correct size, as well as order-one phases in the PMNS matrix. We compare with the alternative possibility of introducing multiple scales of compositeness for leptons, that also allow to evade flavor and CP constraints. Finally, we examine violations of lepton flavor universality in B-meson semi-leptonic decays. The neutral-current anomalies can be accommodated, predicting strong correlations among different lepton flavors, with a few channels close to the experimental sensitivity.http://link.springer.com/article/10.1007/JHEP10(2018)017Beyond Standard ModelTechnicolor and Composite ModelsNeutrino PhysicsEffective Field Theories |
| spellingShingle | Michele Frigerio Marco Nardecchia Javi Serra Luca Vecchi The bearable compositeness of leptons Journal of High Energy Physics Beyond Standard Model Technicolor and Composite Models Neutrino Physics Effective Field Theories |
| title | The bearable compositeness of leptons |
| title_full | The bearable compositeness of leptons |
| title_fullStr | The bearable compositeness of leptons |
| title_full_unstemmed | The bearable compositeness of leptons |
| title_short | The bearable compositeness of leptons |
| title_sort | bearable compositeness of leptons |
| topic | Beyond Standard Model Technicolor and Composite Models Neutrino Physics Effective Field Theories |
| url | http://link.springer.com/article/10.1007/JHEP10(2018)017 |
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