A search for the Higgs boson decaying into a photon and a pair of electrons or muons with an invariant mass m(ll) < 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 -> ll(gamma) 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 mu = 1.5 +/- 0.5. The Higgs boson production cross-section times the H -> ll(gamma) branching ratio for m(ll) < 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 root √s=13 TeV with the ATLAS detector / Aad, G., Abbott, B., Abbott, D.c., Abud, A.a., Abeling, K., Abhayasinghe, D.k., Abidi, S.h., Abouzeid, O.s., Abraham, N.l., Abramowicz, H., Abreu, H., Abulaiti, Y., Hoffman, A., Acharya, B.s., Achkar, B., Adam, L., Bourdarios, C.a., Adamczyk, L., Adamek, L., Adelman, J., et al.. - In: PHYSICS LETTERS. SECTION B. - ISSN 0370-2693. - 819:(2021), pp. 136412.--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 root √s=13 TeV with the ATLAS detector
Gonella LMembro del Collaboration Group
;
2021-01-01
Abstract
A search for the Higgs boson decaying into a photon and a pair of electrons or muons with an invariant mass m(ll) < 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 -> ll(gamma) 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 mu = 1.5 +/- 0.5. The Higgs boson production cross-section times the H -> ll(gamma) branching ratio for m(ll) < 30 GeV is determined to be 8.7(-2.7)(+2.8) fb.| File | Dimensione | Formato | |
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Gonella - Evidence for Higgs boson decays.pdf
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