Displaced vertex signatures of doubly charged scalars in the type-II seesaw and its left-right extensions
Abstract The type-II seesaw mechanism with an isospin-triplet scalar Δ L provides one of the most compelling explanations for the observed smallness of neutrino masses. The triplet contains a doubly-charged component H L ± ± $$ {H}_{{}^L}^{\pm \pm } $$ , which dominantly decays to either same-sign d...
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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 |
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| Online Access: | http://link.springer.com/article/10.1007/JHEP10(2018)199 |
| _version_ | 1818521751194173440 |
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| author | P. S. Bhupal Dev Yongchao Zhang |
| author_facet | P. S. Bhupal Dev Yongchao Zhang |
| author_sort | P. S. Bhupal Dev |
| collection | DOAJ |
| description | Abstract The type-II seesaw mechanism with an isospin-triplet scalar Δ L provides one of the most compelling explanations for the observed smallness of neutrino masses. The triplet contains a doubly-charged component H L ± ± $$ {H}_{{}^L}^{\pm \pm } $$ , which dominantly decays to either same-sign dileptons or to a pair of W bosons, depending on the size of the triplet vacuum expectation value. However, there exists a range of Yukawa couplings f L of the triplet to the charged leptons, wherein a relatively light H L ± ± $$ {H}_{{}^L}^{\pm \pm } $$ tends to be long-lived, giving rise to distinct displaced-vertex signatures at the high-energy colliders. We find that the displaced vertex signals from the leptonic decays H L ± ± → ℓ α ± ℓ β ± $$ {H}_{{}^L}^{\pm \pm}\to {\ell}_{\alpha}^{\pm }{\ell}_{{}^{\beta}}^{\pm } $$ could probe a broad parameter space with 10−10 ≲ |f L | ≲ 10−6 and 45.6 GeV < M H L ± ± ≲ 200 GeV $$ 45.6\ GeV<{M}_{H_L^{\pm \pm }}\lesssim 200\ GeV $$ at the high-luminosity LHC. Similar sensitivity can also be achieved at a future 1 TeV e + e − collider. The mass reach can be extended to about 500GeV at a future 100TeV proton-proton collider. Similar conclusions apply for the right-handed triplet H R ± ± $$ {H}_{{}^R}^{\pm \pm } $$ in the TeV-scale left-right symmetric models, which provide a natural embedding of the type-II seesaw. We show that the displaced vertex signals are largely complementary to the prompt same-sign dilepton pair searches at the LHC and the low-energy, high-intensity/precision measurements, such as neutrinoless double beta decay, charged lepton flavor violation, electron and muon anomalous magnetic moments, muonium-antimuonium oscillation and Møller scattering. |
| first_indexed | 2024-12-11T01:55:33Z |
| format | Article |
| id | doaj.art-4782a3bd3f6541efa62e8b1117278197 |
| institution | Directory Open Access Journal |
| issn | 1029-8479 |
| language | English |
| last_indexed | 2024-12-11T01:55:33Z |
| publishDate | 2018-10-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | Journal of High Energy Physics |
| spelling | doaj.art-4782a3bd3f6541efa62e8b11172781972022-12-22T01:24:37ZengSpringerOpenJournal of High Energy Physics1029-84792018-10-0120181015210.1007/JHEP10(2018)199Displaced vertex signatures of doubly charged scalars in the type-II seesaw and its left-right extensionsP. S. Bhupal Dev0Yongchao Zhang1Department of Physics and McDonnell Center for the Space Sciences, Washington UniversityDepartment of Physics and McDonnell Center for the Space Sciences, Washington UniversityAbstract The type-II seesaw mechanism with an isospin-triplet scalar Δ L provides one of the most compelling explanations for the observed smallness of neutrino masses. The triplet contains a doubly-charged component H L ± ± $$ {H}_{{}^L}^{\pm \pm } $$ , which dominantly decays to either same-sign dileptons or to a pair of W bosons, depending on the size of the triplet vacuum expectation value. However, there exists a range of Yukawa couplings f L of the triplet to the charged leptons, wherein a relatively light H L ± ± $$ {H}_{{}^L}^{\pm \pm } $$ tends to be long-lived, giving rise to distinct displaced-vertex signatures at the high-energy colliders. We find that the displaced vertex signals from the leptonic decays H L ± ± → ℓ α ± ℓ β ± $$ {H}_{{}^L}^{\pm \pm}\to {\ell}_{\alpha}^{\pm }{\ell}_{{}^{\beta}}^{\pm } $$ could probe a broad parameter space with 10−10 ≲ |f L | ≲ 10−6 and 45.6 GeV < M H L ± ± ≲ 200 GeV $$ 45.6\ GeV<{M}_{H_L^{\pm \pm }}\lesssim 200\ GeV $$ at the high-luminosity LHC. Similar sensitivity can also be achieved at a future 1 TeV e + e − collider. The mass reach can be extended to about 500GeV at a future 100TeV proton-proton collider. Similar conclusions apply for the right-handed triplet H R ± ± $$ {H}_{{}^R}^{\pm \pm } $$ in the TeV-scale left-right symmetric models, which provide a natural embedding of the type-II seesaw. We show that the displaced vertex signals are largely complementary to the prompt same-sign dilepton pair searches at the LHC and the low-energy, high-intensity/precision measurements, such as neutrinoless double beta decay, charged lepton flavor violation, electron and muon anomalous magnetic moments, muonium-antimuonium oscillation and Møller scattering.http://link.springer.com/article/10.1007/JHEP10(2018)199Beyond Standard ModelHiggs PhysicsNeutrino Physics |
| spellingShingle | P. S. Bhupal Dev Yongchao Zhang Displaced vertex signatures of doubly charged scalars in the type-II seesaw and its left-right extensions Journal of High Energy Physics Beyond Standard Model Higgs Physics Neutrino Physics |
| title | Displaced vertex signatures of doubly charged scalars in the type-II seesaw and its left-right extensions |
| title_full | Displaced vertex signatures of doubly charged scalars in the type-II seesaw and its left-right extensions |
| title_fullStr | Displaced vertex signatures of doubly charged scalars in the type-II seesaw and its left-right extensions |
| title_full_unstemmed | Displaced vertex signatures of doubly charged scalars in the type-II seesaw and its left-right extensions |
| title_short | Displaced vertex signatures of doubly charged scalars in the type-II seesaw and its left-right extensions |
| title_sort | displaced vertex signatures of doubly charged scalars in the type ii seesaw and its left right extensions |
| topic | Beyond Standard Model Higgs Physics Neutrino Physics |
| url | http://link.springer.com/article/10.1007/JHEP10(2018)199 |
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