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

0548512 - FZÚ 2022 RIV NL eng J - Journal Article
Aad, G. - Abbott, B. - Abbott, D.C. - Chudoba, Jiří - Hejbal, Jiří - Hladík, Ondřej - Jačka, Petr - Kepka, Oldřich - Kroll, Jiří - Kupčo, Alexander - Latoňová, Věra - Lokajíček, Miloš - Lysák, Roman - Marčišovský, Michal - Mikeštíková, Marcela - Němeček, Stanislav - Penc, Ondřej - Šícho, Petr - Staroba, Pavel - Svatoš, Michal - Taševský, Marek … Total 2879 authors
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.
Physics Letters. B. Roč. 819, Aug (2021), č. článku 136412. ISSN 0370-2693. E-ISSN 1873-2445
R&D Projects: GA MŠMT(CZ) LTT17018
Research Infrastructure: CERN-CZ II - 90104
Institutional support: RVO:68378271
Keywords : ATLAS * CERN LHC Coll * channel cross section: branching ratio: measured * dilepton: mass spectrum
OECD category: Particles and field physics
Impact factor: 4.950, year: 2021
Method of publishing: Open access

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.
Permanent Link: http://hdl.handle.net/11104/0324572