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, A., Alviggi, M., Canale, V., Della Pietra, M., Merola, L., Massarotti, P., Conventi, F., Rossi, E., Carlino, G., De Asmundis, R., Di Donato, C., Doria, A., Iengo, P., Izzo, V., Perrella, S., Sekhniaidze, G., Cirotto, F., Lavorgna, M., Giannini, A., Atlas, C., et al.. - 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;LOFFREDO, Salvatore
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.
