A search for a light pseudoscalar Higgs boson (a) decaying from the 125 GeV (or a heavier) scalar Higgs boson (H) is performed using the 2016 LHC proton-proton collision data at s = 13 TeV, corresponding to an integrated luminosity of 35.9 fb−1, collected by the CMS experiment. The analysis considers gluon fusion and vector boson fusion production of the H, followed by the decay H → aa → μμττ, and considers pseudoscalar masses in the range 3.6 < ma< 21 GeV. Because of the large mass difference between the H and the a bosons and the small masses of the a boson decay products, both the μμ and the ττ pairs have high Lorentz boost and are collimated. The ττ reconstruction efficiency is increased by modifying the standard technique for hadronic τ lepton decay reconstruction to account for a nearby muon. No significant signal is observed. Model-independent limits are set at 95% confidence level, as a function of ma, on the branching fraction (ℬ) for H → aa → μμττ, down to 1.5 (2.0) × 10−4 for mH = 125 (300) GeV. Model-dependent limits on ℬ(H → aa) are set within the context of two Higgs doublets plus singlet models, with the most stringent results obtained for Type-III models. These results extend current LHC searches for heavier a bosons that decay to resolved lepton pairs and provide the first such bounds for an H boson with a mass above 125 GeV. [Figure not available: see fulltext.].

Sirunyan, A., Tumasyan, A., Adam, W., Ambrogi, F., Bergauer, T., Dragicevic, M., et al. (2020). Search for a light pseudoscalar Higgs boson in the boosted μμττ final state in proton-proton collisions at √s = 13 TeV. JOURNAL OF HIGH ENERGY PHYSICS, 2020(8) [10.1007/JHEP08(2020)139].

Search for a light pseudoscalar Higgs boson in the boosted μμττ final state in proton-proton collisions at √s = 13 TeV

Benaglia, A.;Beschi, A.;Brivio, F.;Cetorelli, F.;Ciriolo, V.;De Guio, F.;Dinardo, M. E.;Ghezzi, A.;Govoni, P.;Guzzi, L.;Malberti, M.;Monti, F.;Moroni, L.;Paganoni, M.;Ragazzi, S.;Tabarelli de Fatis, T.;Valsecchi, D.;Zuolo, D.;Lucchini, M. T.;
2020

Abstract

A search for a light pseudoscalar Higgs boson (a) decaying from the 125 GeV (or a heavier) scalar Higgs boson (H) is performed using the 2016 LHC proton-proton collision data at s = 13 TeV, corresponding to an integrated luminosity of 35.9 fb−1, collected by the CMS experiment. The analysis considers gluon fusion and vector boson fusion production of the H, followed by the decay H → aa → μμττ, and considers pseudoscalar masses in the range 3.6 < ma< 21 GeV. Because of the large mass difference between the H and the a bosons and the small masses of the a boson decay products, both the μμ and the ττ pairs have high Lorentz boost and are collimated. The ττ reconstruction efficiency is increased by modifying the standard technique for hadronic τ lepton decay reconstruction to account for a nearby muon. No significant signal is observed. Model-independent limits are set at 95% confidence level, as a function of ma, on the branching fraction (ℬ) for H → aa → μμττ, down to 1.5 (2.0) × 10−4 for mH = 125 (300) GeV. Model-dependent limits on ℬ(H → aa) are set within the context of two Higgs doublets plus singlet models, with the most stringent results obtained for Type-III models. These results extend current LHC searches for heavier a bosons that decay to resolved lepton pairs and provide the first such bounds for an H boson with a mass above 125 GeV. [Figure not available: see fulltext.].
Articolo in rivista - Articolo scientifico
Physics; LHC; CMS
English
2020
2020
8
139
none
Sirunyan, A., Tumasyan, A., Adam, W., Ambrogi, F., Bergauer, T., Dragicevic, M., et al. (2020). Search for a light pseudoscalar Higgs boson in the boosted μμττ final state in proton-proton collisions at √s = 13 TeV. JOURNAL OF HIGH ENERGY PHYSICS, 2020(8) [10.1007/JHEP08(2020)139].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/308911
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