A search for exotic decays of the 125 GeV Higgs boson into a pair of new spin-0 particles, H → aa, where one decays into a photon pair and the other into a τ -lepton pair, is presented. Hadronic decays of the τ -leptons are considered and reconstructed using a dedicated tagger for collimated τ -lepton pairs. The search uses 140 fb−1 of proton-proton collision data at a centre-of-mass energy of √ s = 13 TeV recorded between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider. The search is performed in the mass range of the a boson between 10 GeV and 60 GeV. No significant excess of events is observed above the Standard Model background expectation. Model-independent upper limits at 95% confidence level are set on the branching ratio of the Higgs boson to the γγτ τ final state, B(H → aa → γγτ τ ), ranging from 0.2% to 2%, depending on the a-boson mass hypothesis.

Null, N., Aad, G., Aakvaag, E., Abbott, B., Abdelhameed, S., Abeling, K., et al. (2025). Search for Higgs boson decays into a pair of pseudoscalar particles in the γγτhadτhad final state using pp collisions at √s = 13 TeV with the ATLAS detector. JOURNAL OF HIGH ENERGY PHYSICS, 2025(3), 0-38 [10.1007/jhep03(2025)190].

Search for Higgs boson decays into a pair of pseudoscalar particles in the γγτhadτhad final state using pp collisions at √s = 13 TeV with the ATLAS detector

Alberghi, G. L.;Alfonsi, F.;Ballabene, E.;Bellagamba, L.;Bianco, G.;Boscherini, D.;Bruni, A.;Carratta, G.;Cremonini, D.;De Castro, S.;Fabbri, F.;Fabbri, L.;Franchini, M.;Gabrielli, A.;Giacobbe, B.;Lasagni Manghi, F.;Levrini, G.;Nechaeva, S.;Polini, A.;Rinaldi, L.;Romano, M.;Sanzani, E.;Sbarra, C.;Sbrizzi, A.;Semprini-Cesari, N.;Sioli, M.;Todome, K.;Valentinetti, S.;Villa, M.;Vittori, C.;Vivarelli, I.;Zoccoli, A.;
2025

Abstract

A search for exotic decays of the 125 GeV Higgs boson into a pair of new spin-0 particles, H → aa, where one decays into a photon pair and the other into a τ -lepton pair, is presented. Hadronic decays of the τ -leptons are considered and reconstructed using a dedicated tagger for collimated τ -lepton pairs. The search uses 140 fb−1 of proton-proton collision data at a centre-of-mass energy of √ s = 13 TeV recorded between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider. The search is performed in the mass range of the a boson between 10 GeV and 60 GeV. No significant excess of events is observed above the Standard Model background expectation. Model-independent upper limits at 95% confidence level are set on the branching ratio of the Higgs boson to the γγτ τ final state, B(H → aa → γγτ τ ), ranging from 0.2% to 2%, depending on the a-boson mass hypothesis.
2025
Null, N., Aad, G., Aakvaag, E., Abbott, B., Abdelhameed, S., Abeling, K., et al. (2025). Search for Higgs boson decays into a pair of pseudoscalar particles in the γγτhadτhad final state using pp collisions at √s = 13 TeV with the ATLAS detector. JOURNAL OF HIGH ENERGY PHYSICS, 2025(3), 0-38 [10.1007/jhep03(2025)190].
Null, Null; Aad, G.; Aakvaag, E.; Abbott, B.; Abdelhameed, S.; Abeling, K.; Abicht, N. J.; Abidi, S. H.; Aboelela, M.; Aboulhorma, A.; Abramowicz, H.;...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/1044087
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