Direct constraint on the Higgs–charm coupling from a search for Higgs boson decays into charm quarks with the ATLAS detector

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Fecha
2022-08
Profesor/a Guía
Facultad/escuela
Idioma
en
Título de la revista
ISSN de la revista
Título del volumen
Editor
Institute for Ionics
Nombre de Curso
Licencia CC
CC BY 4.0 DEED Attribution 4.0 International
Licencia CC
https://creativecommons.org/licenses/by/4.0/deed.en
Resumen
A search for the Higgs boson decaying into a pair of charm quarks is presented. The analysis uses proton–proton collisions to target the production of a Higgs boson in association with a leptonically decaying W or Z boson. The dataset delivered by the LHC at a centre-of-mass energy of [InlineEquation not available: see fulltext.] and recorded by the ATLAS detector corresponds to an integrated luminosity of 139 fb-1. Flavour-tagging algorithms are used to identify jets originating from the hadronisation of charm quarks. The analysis method is validated with the simultaneous measurement of WW, WZ and ZZ production, with observed (expected) significances of 2.6 (2.2) standard deviations above the background-only prediction for the (W/ Z) Z(→ cc¯) process and 3.8 (4.6) standard deviations for the (W/ Z) W(→ cq) process. The (W/ Z) H(→ cc¯) search yields an observed (expected) upper limit of 26 (31) times the predicted Standard Model cross-section times branching fraction for a Higgs boson with a mass of [InlineEquation not available: see fulltext.], corresponding to an observed (expected) constraint on the charm Yukawa coupling modifier |κc|<8.5(12.4), at the 95% confidence level. A combination with the ATLAS (W/ Z) H, H→ bb¯ analysis is performed, allowing the ratio κc/ κb to be constrained to less than 4.5 at the 95% confidence level, smaller than the ratio of the b- and c-quark masses, and therefore determines the Higgs-charm coupling to be weaker than the Higgs-bottom coupling at the 95% confidence level. © 2022, The Author(s).
Notas
Indexación: Scopus.
Palabras clave
Boson, Partons, Higgs Bosons
Citación
European Physical Journal C, Volume 82, Issue 8, August 2022, Article number 717
DOI
10.1140/epjc/s10052-022-10588-3
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