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Probing top-quark couplings indirectly at Higgs factories
We perform a global effective-field-theory analysis to assess the combined precision of Higgs couplings, triple gauge-boson couplings, and top-quark couplings, at future circular e + e − colliders, with a focus on runs below the production threshold. Deviations in the top-quark sector entering as on...
Autores principales: | , , , |
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Lenguaje: | eng |
Publicado: |
2018
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Materias: | |
Acceso en línea: | https://dx.doi.org/10.1088/1674-1137/42/12/123107 http://cds.cern.ch/record/2638204 |
_version_ | 1780959967981862912 |
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author | Durieux, Gauthier Gu, Jiayin Vryonidou, Eleni Zhang, Cen |
author_facet | Durieux, Gauthier Gu, Jiayin Vryonidou, Eleni Zhang, Cen |
author_sort | Durieux, Gauthier |
collection | CERN |
description | We perform a global effective-field-theory analysis to assess the combined precision of Higgs couplings, triple gauge-boson couplings, and top-quark couplings, at future circular e + e − colliders, with a focus on runs below the production threshold. Deviations in the top-quark sector entering as one-loop corrections are consistently taken into account in the Higgs and diboson processes. We find that future lepton colliders running at center-of-mass energies below the production threshold can still provide useful information on top-quark couplings, by measuring virtual top-quark effects. With rate and differential measurements, the indirect individual sensitivity achievable is better than at the high-luminosity LHC. However, strong correlations between the extracted top-quark and Higgs couplings are also present and lead to much weaker global constraints on top-quark couplings. This implies that a direct probe of top-quark couplings above the production threshold is also helpful for the determination of Higgs and triple-gauge-boson couplings. In addition, we find that below the production threshold, the top-quark Yukawa coupling can be determined by its loop corrections to all Higgs production and decay channels. Degeneracy with the ggh coupling can be resolved, and even a global limit is competitive with the prospects of a linear collider above the threshold. This provides an additional means of determining the top-quark Yukawa coupling indirectly at lepton colliders. |
id | cern-2638204 |
institution | Organización Europea para la Investigación Nuclear |
language | eng |
publishDate | 2018 |
record_format | invenio |
spelling | cern-26382042021-07-15T22:59:11Zdoi:10.1088/1674-1137/42/12/123107http://cds.cern.ch/record/2638204engDurieux, GauthierGu, JiayinVryonidou, EleniZhang, CenProbing top-quark couplings indirectly at Higgs factorieshep-exParticle Physics - Experimenthep-phParticle Physics - PhenomenologyWe perform a global effective-field-theory analysis to assess the combined precision of Higgs couplings, triple gauge-boson couplings, and top-quark couplings, at future circular e + e − colliders, with a focus on runs below the production threshold. Deviations in the top-quark sector entering as one-loop corrections are consistently taken into account in the Higgs and diboson processes. We find that future lepton colliders running at center-of-mass energies below the production threshold can still provide useful information on top-quark couplings, by measuring virtual top-quark effects. With rate and differential measurements, the indirect individual sensitivity achievable is better than at the high-luminosity LHC. However, strong correlations between the extracted top-quark and Higgs couplings are also present and lead to much weaker global constraints on top-quark couplings. This implies that a direct probe of top-quark couplings above the production threshold is also helpful for the determination of Higgs and triple-gauge-boson couplings. In addition, we find that below the production threshold, the top-quark Yukawa coupling can be determined by its loop corrections to all Higgs production and decay channels. Degeneracy with the ggh coupling can be resolved, and even a global limit is competitive with the prospects of a linear collider above the threshold. This provides an additional means of determining the top-quark Yukawa coupling indirectly at lepton colliders.We perform a global effective-field-theory analysis to assess the combined precision on Higgs couplings, triple gauge-boson couplings, and top-quark couplings, at future circular $e^+e^-$ colliders, with a focus on runs below the $t\bar t$ production threshold. Deviations in the top-quark sector entering as one-loop corrections are consistently taken into account in Higgs and diboson processes. We find that future lepton colliders running at center-of-mass energies below the $t\bar t$ production threshold can still provide useful information on top-quark couplings, by measuring virtual top-quark effects. With rate and differential measurements, the indirect individual sensitivity achievable is better than at the high-luminosity LHC. However, strong correlations between the extracted top-quark and Higgs couplings are also present and lead to much weaker global constraints on top-quark couplings. This implies that a direct probe of top-quark couplings above the $t\bar t$ production threshold is helpful also for the determination of Higgs and triple-gauge-boson couplings. In addition, we find that below the $e^+e^-\to t\bar th$ production threshold, the top-quark Yukawa coupling can be determined by its loop corrections to all Higgs production and decay channels. Degeneracy with the $ggh$ coupling can be resolved, and even a global limit is competitive with the prospects of a linear collider above the threshold. This provides an additional means of determining the top-quark Yukawa coupling indirectly at lepton colliders.arXiv:1809.03520DESY-18-142DESY 18-142CERN-TH-2018-193MITP/18-081oai:cds.cern.ch:26382042018-09-10 |
spellingShingle | hep-ex Particle Physics - Experiment hep-ph Particle Physics - Phenomenology Durieux, Gauthier Gu, Jiayin Vryonidou, Eleni Zhang, Cen Probing top-quark couplings indirectly at Higgs factories |
title | Probing top-quark couplings indirectly at Higgs factories |
title_full | Probing top-quark couplings indirectly at Higgs factories |
title_fullStr | Probing top-quark couplings indirectly at Higgs factories |
title_full_unstemmed | Probing top-quark couplings indirectly at Higgs factories |
title_short | Probing top-quark couplings indirectly at Higgs factories |
title_sort | probing top-quark couplings indirectly at higgs factories |
topic | hep-ex Particle Physics - Experiment hep-ph Particle Physics - Phenomenology |
url | https://dx.doi.org/10.1088/1674-1137/42/12/123107 http://cds.cern.ch/record/2638204 |
work_keys_str_mv | AT durieuxgauthier probingtopquarkcouplingsindirectlyathiggsfactories AT gujiayin probingtopquarkcouplingsindirectlyathiggsfactories AT vryonidoueleni probingtopquarkcouplingsindirectlyathiggsfactories AT zhangcen probingtopquarkcouplingsindirectlyathiggsfactories |