Searches for the exclusive decays of Higgs and Z bosons into a vector quarkonium state and a photon are performed in the μ+μ-γ final state with a proton–proton collision data sample corresponding to an integrated luminosity of 139 fb - 1 collected at s=13 TeV with the ATLAS detector at the CERN Large Hadron Collider. The observed data are compatible with the expected backgrounds. The 95% confidence-level upper limits on the branching fractions of the Higgs boson decays into J/ψγ , ψ(2S)γ , and Υ(1S,2S,3S)γ are found to be 2.0 × 10 - 4 , 10.5 × 10 - 4 , and (2.5 , 4.2 , 3.4) × 10 - 4 , respectively, assuming Standard Model production of the Higgs boson. The corresponding 95% CL upper limits on the branching fractions of the Z boson decays are 1.2 × 10 - 6 , 2.4 × 10 - 6 , and (1.1 , 1.3 , 2.4) × 10 - 6 . An observed 95% CL interval of (- 133 , 175) is obtained for the κc/ κγ ratio of Higgs boson coupling modifiers, and a 95% CL interval of (- 37 , 40) is obtained for κb/ κγ .
Searches for exclusive Higgs and Z boson decays into a vector quarkonium state and a photon using 139 fb - 1 of ATLAS √s=13 TeV proton–proton collision data / Betti, A.; De Salvo, A.; Di Domenico, A.; Dionisi, C.; Bini, C.; Luci, C.; Pompa Pacchi, E.; Morodei, F.; Lacava, F.; Safai Tehrani, F.; Artoni, G.; Santi, L.; Martinelli, L.; Maiani, L; Bauce, M.; Gauzzi, P.; Gentile, S.; Falciano, S.; Giagu, S.; Ippolito, V.; Padovano, G.. - In: THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS. - ISSN 1434-6044. - 83:9(2023). [10.1140/epjc/s10052-023-11869-1]
Searches for exclusive Higgs and Z boson decays into a vector quarkonium state and a photon using 139 fb - 1 of ATLAS √s=13 TeV proton–proton collision data
Betti A.;De Salvo A.;Di Domenico A.;Dionisi C.;Bini C.;Luci C.;Pompa Pacchi E.;Morodei F.;Lacava F.;Safai Tehrani F.;Artoni G.;Santi L.;Martinelli L.;Maiani L;Bauce M.;Gauzzi P.;Gentile S.;Falciano S.;Giagu S.;Ippolito V.;Padovano G.
2023
Abstract
Searches for the exclusive decays of Higgs and Z bosons into a vector quarkonium state and a photon are performed in the μ+μ-γ final state with a proton–proton collision data sample corresponding to an integrated luminosity of 139 fb - 1 collected at s=13 TeV with the ATLAS detector at the CERN Large Hadron Collider. The observed data are compatible with the expected backgrounds. The 95% confidence-level upper limits on the branching fractions of the Higgs boson decays into J/ψγ , ψ(2S)γ , and Υ(1S,2S,3S)γ are found to be 2.0 × 10 - 4 , 10.5 × 10 - 4 , and (2.5 , 4.2 , 3.4) × 10 - 4 , respectively, assuming Standard Model production of the Higgs boson. The corresponding 95% CL upper limits on the branching fractions of the Z boson decays are 1.2 × 10 - 6 , 2.4 × 10 - 6 , and (1.1 , 1.3 , 2.4) × 10 - 6 . An observed 95% CL interval of (- 133 , 175) is obtained for the κc/ κγ ratio of Higgs boson coupling modifiers, and a 95% CL interval of (- 37 , 40) is obtained for κb/ κγ .I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
