A search for the Higgs boson decaying into a photon and a pair of electrons or muons with an invariant mass mℓℓ<30 GeV is presented. The analysis is performed using 139 fb−1 of proton–proton collision data, produced by the LHC at a centre-of-mass energy of 13 TeV and collected by the ATLAS experiment. Evidence for the H→ℓℓγ process is found with a significance of 3.2 over the background-only hypothesis, compared to an expected significance of 2.1 for the Standard Model prediction. The best-fit value of the signal-strength parameter, defined as the ratio of the observed signal yield to the one expected in the Standard Model, is μ=1.5±0.5. The Higgs boson production cross-section times the H→ℓℓγ branching ratio for mℓℓ<30 GeV is determined to be 8.7−2.7+2.8 fb.
Evidence for Higgs boson decays to a low-mass dilepton system and a photon in pp collisions at s=13 TeV with the ATLAS detector / Aloisio, Alberto; Alviggi, Mariagrazia; Canale, Vincenzo; Della Pietra, Massimo; Merola, Leonardo; Massarotti, Paolo; Conventi, Francesco; Rossi, Elvira; Carlino, Giampaolo; de Asmundis, Riccardo; Di Donato, Camilla; Doria, Alessandra; Iengo, Paolo; Izzo, Vincenzo; Perrella, Sabrina; Sekhniaidze, Givi; Cirotto, Francesco; Lavorgna, Marco; Giannini, Antonio; Atlas, Collaboration. - In: PHYSICS LETTERS. SECTION B. - ISSN 0370-2693. - 819:(2021), p. 136412. [10.1016/j.physletb.2021.136412]
Evidence for Higgs boson decays to a low-mass dilepton system and a photon in pp collisions at s=13 TeV with the ATLAS detector
Aloisio, Alberto;Alviggi, MariaGrazia;Canale, Vincenzo;Della Pietra, Massimo;Merola, Leonardo;Massarotti, Paolo;Rossi, Elvira;Perrella, Sabrina;Cirotto, Francesco;Lavorgna, Marco;Giannini, Antonio;
2021
Abstract
A search for the Higgs boson decaying into a photon and a pair of electrons or muons with an invariant mass mℓℓ<30 GeV is presented. The analysis is performed using 139 fb−1 of proton–proton collision data, produced by the LHC at a centre-of-mass energy of 13 TeV and collected by the ATLAS experiment. Evidence for the H→ℓℓγ process is found with a significance of 3.2 over the background-only hypothesis, compared to an expected significance of 2.1 for the Standard Model prediction. The best-fit value of the signal-strength parameter, defined as the ratio of the observed signal yield to the one expected in the Standard Model, is μ=1.5±0.5. The Higgs boson production cross-section times the H→ℓℓγ branching ratio for mℓℓ<30 GeV is determined to be 8.7−2.7+2.8 fb.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
