Observation of electroweak production of two jets in association with an isolated photon and missing transverse momentum, and search for a Higgs boson decaying into invisible particles at 13 TeV with the ATLAS detector

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Fecha
2022-02
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
Attribution 4.0 International CC BY 4.0 Deed
Licencia CC
https://creativecommons.org/licenses/by/4.0/
Resumen
This paper presents a measurement of the electroweak production of two jets in association with a Zγ pair, with the Z boson decaying into two neutrinos. It also presents a search for invisible or partially invisible decays of a Higgs boson with a mass of 125 GeV produced through vector-boson fusion with a photon in the final state. These results use data from LHC proton–proton collisions at s = 13 TeV collected with the ATLAS detector and corresponding to an integrated luminosity of 139 fb - 1. The event signature, shared by all benchmark processes considered for the measurements and searches, is characterized by a significant amount of unbalanced transverse momentum and a photon in the final state, in addition to a pair of forward jets. Electroweak Zγ production in association with two jets is observed in this final state with a significance of 5.2 (5.1 expected) standard deviations. The measured fiducial cross-section for this process is 1.31 ± 0.29 fb. An observed (expected) upper limit of 0.37 (0.34-0.10+0.15) at 95% confidence level is set on the branching ratio of a 125 GeV Higgs boson to invisible particles, assuming the Standard Model production cross-section. The signature is also interpreted in the context of decays of a Higgs boson into a photon and a dark photon. An observed (expected) 95% CL upper limit on the branching ratio for this decay is set at 0.018 (0.017-0.005+0.007), assuming the Standard Model production cross-section for a 125 GeV Higgs boson. © 2022, The Author(s).
Notas
Indexación: Scopus.
Palabras clave
Hadron, Lepton, Standard Model
Citación
European Physical Journal C, Volume 82, Issue 2, February 2022, Article number 105
DOI
10.1140/epjc/s10052-021-09878-z
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