Multi-Higgs doublet models: physical parametrization, sum rules and unitarity bounds
Abstract If the scalar sector of the Standard Model is non-minimal, one might expect multiple generations of the hypercharge-1/2 scalar doublet analogous to the generational structure of the fermions. In this work, we examine the structure of a Higgs sector consisting of N Higgs doublets (where N ≥...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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SpringerOpen
2017-11-01
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| Series: | Journal of High Energy Physics |
| Subjects: | |
| Online Access: | http://link.springer.com/article/10.1007/JHEP11(2017)095 |
| _version_ | 1811264299014815744 |
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| author | Miguel P. Bento Howard E. Haber J. C. Romão João P. Silva |
| author_facet | Miguel P. Bento Howard E. Haber J. C. Romão João P. Silva |
| author_sort | Miguel P. Bento |
| collection | DOAJ |
| description | Abstract If the scalar sector of the Standard Model is non-minimal, one might expect multiple generations of the hypercharge-1/2 scalar doublet analogous to the generational structure of the fermions. In this work, we examine the structure of a Higgs sector consisting of N Higgs doublets (where N ≥ 2). It is particularly convenient to work in the so-called charged Higgs basis, in which the neutral Higgs vacuum expectation value resides entirely in the first Higgs doublet, and the charged components of remaining N − 1 Higgs doublets are mass-eigenstate fields. We elucidate the interactions of the gauge bosons with the physical Higgs scalars and the Goldstone bosons and show that they are determined by an N × 2N matrix. This matrix depends on (N − 1)(2N − 1) real parameters that are associated with the mixing of the neutral Higgs fields in the charged Higgs basis. Among these parameters, N − 1 are unphysical (and can be removed by rephasing the physical charged Higgs fields), and the remaining 2(N − 1)2 parameters are physical. We also demonstrate a particularly simple form for the cubic interaction and some of the quartic interactions of the Goldstone bosons with the physical Higgs scalars. These results are applied in the derivation of Higgs coupling sum rules and tree-level unitarity bounds that restrict the size of the quartic scalar couplings. In particular, new applications to three Higgs doublet models with an order-4 CP symmetry and with a ℤ3 $$ {\mathbb{Z}}_3 $$ symmetry, respectively, are presented. |
| first_indexed | 2024-04-12T20:01:47Z |
| format | Article |
| id | doaj.art-dffb51c822464bc18c02f9e95852baa9 |
| institution | Directory Open Access Journal |
| issn | 1029-8479 |
| language | English |
| last_indexed | 2024-04-12T20:01:47Z |
| publishDate | 2017-11-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | Journal of High Energy Physics |
| spelling | doaj.art-dffb51c822464bc18c02f9e95852baa92022-12-22T03:18:31ZengSpringerOpenJournal of High Energy Physics1029-84792017-11-0120171116710.1007/JHEP11(2017)095Multi-Higgs doublet models: physical parametrization, sum rules and unitarity boundsMiguel P. Bento0Howard E. Haber1J. C. Romão2João P. Silva3Centro de Física Teórica de Partículas (CFTP) and Departamento de Física, Instituto Superior Técnico, University of LisbonSanta Cruz Institute for Particle Physics, University of CaliforniaCentro de Física Teórica de Partículas (CFTP) and Departamento de Física, Instituto Superior Técnico, University of LisbonCentro de Física Teórica de Partículas (CFTP) and Departamento de Física, Instituto Superior Técnico, University of LisbonAbstract If the scalar sector of the Standard Model is non-minimal, one might expect multiple generations of the hypercharge-1/2 scalar doublet analogous to the generational structure of the fermions. In this work, we examine the structure of a Higgs sector consisting of N Higgs doublets (where N ≥ 2). It is particularly convenient to work in the so-called charged Higgs basis, in which the neutral Higgs vacuum expectation value resides entirely in the first Higgs doublet, and the charged components of remaining N − 1 Higgs doublets are mass-eigenstate fields. We elucidate the interactions of the gauge bosons with the physical Higgs scalars and the Goldstone bosons and show that they are determined by an N × 2N matrix. This matrix depends on (N − 1)(2N − 1) real parameters that are associated with the mixing of the neutral Higgs fields in the charged Higgs basis. Among these parameters, N − 1 are unphysical (and can be removed by rephasing the physical charged Higgs fields), and the remaining 2(N − 1)2 parameters are physical. We also demonstrate a particularly simple form for the cubic interaction and some of the quartic interactions of the Goldstone bosons with the physical Higgs scalars. These results are applied in the derivation of Higgs coupling sum rules and tree-level unitarity bounds that restrict the size of the quartic scalar couplings. In particular, new applications to three Higgs doublet models with an order-4 CP symmetry and with a ℤ3 $$ {\mathbb{Z}}_3 $$ symmetry, respectively, are presented.http://link.springer.com/article/10.1007/JHEP11(2017)095Beyond Standard ModelHiggs PhysicsCP violationDiscrete Symmetries |
| spellingShingle | Miguel P. Bento Howard E. Haber J. C. Romão João P. Silva Multi-Higgs doublet models: physical parametrization, sum rules and unitarity bounds Journal of High Energy Physics Beyond Standard Model Higgs Physics CP violation Discrete Symmetries |
| title | Multi-Higgs doublet models: physical parametrization, sum rules and unitarity bounds |
| title_full | Multi-Higgs doublet models: physical parametrization, sum rules and unitarity bounds |
| title_fullStr | Multi-Higgs doublet models: physical parametrization, sum rules and unitarity bounds |
| title_full_unstemmed | Multi-Higgs doublet models: physical parametrization, sum rules and unitarity bounds |
| title_short | Multi-Higgs doublet models: physical parametrization, sum rules and unitarity bounds |
| title_sort | multi higgs doublet models physical parametrization sum rules and unitarity bounds |
| topic | Beyond Standard Model Higgs Physics CP violation Discrete Symmetries |
| url | http://link.springer.com/article/10.1007/JHEP11(2017)095 |
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