A search is described for a Higgs boson decaying into two photons, one of which has an internal conversion to a muon or an electron pair (ℓℓγ). The analysis is performed using proton–proton collision data recorded with the CMS detector at the LHC at a centre-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 19.7 fb−1. The events selected have an opposite-sign muon or electron pair and a high transverse momentum photon. No excess above background has been found in the three-body invariant mass range 120<mℓℓγ<150 GeV120<mℓℓγ<150 GeV, and limits have been derived for the Higgs boson production cross section times branching fraction for the decay H→γ⁎γ→ℓℓγH→γ⁎γ→ℓℓγ, where the dilepton invariant mass is less than 20 GeV. For a Higgs boson with mH=125 GeVmH=125 GeV, a 95% confidence level (CL) exclusion observed (expected) limit is 6.7 (View the MathML source5.9−1.8+2.8) times the standard model prediction. Additionally, an upper limit at 95% CL on the branching fraction of H→(J/ψ)γH→(J/ψ)γ for the 125 GeV Higgs boson is set at 1.5×10−31.5×10−3.
Titolo: | Search for a Higgs boson decaying into gamma* gamma to ll gamma with low dilepton mass in pp collisions at sqrt(s) = 8 TeV |
Autori: | |
Data di pubblicazione: | 2016 |
Rivista: | |
Abstract: | A search is described for a Higgs boson decaying into two photons, one of which has an internal conversion to a muon or an electron pair (ℓℓγ). The analysis is performed using proton–proton collision data recorded with the CMS detector at the LHC at a centre-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 19.7 fb−1. The events selected have an opposite-sign muon or electron pair and a high transverse momentum photon. No excess above background has been found in the three-body invariant mass range 120<mℓℓγ<150 GeV120<mℓℓγ<150 GeV, and limits have been derived for the Higgs boson production cross section times branching fraction for the decay H→γ⁎γ→ℓℓγH→γ⁎γ→ℓℓγ, where the dilepton invariant mass is less than 20 GeV. For a Higgs boson with mH=125 GeVmH=125 GeV, a 95% confidence level (CL) exclusion observed (expected) limit is 6.7 (View the MathML source5.9−1.8+2.8) times the standard model prediction. Additionally, an upper limit at 95% CL on the branching fraction of H→(J/ψ)γH→(J/ψ)γ for the 125 GeV Higgs boson is set at 1.5×10−31.5×10−3. |
Handle: | http://hdl.handle.net/11368/2864223 |
Digital Object Identifier (DOI): | http://dx.doi.org/10.1016/j.physletb.2015.12.039 |
URL: | http://www.sciencedirect.com/science/article/pii/S0370269315009879 |
Appare nelle tipologie: | 1.1 Articolo in Rivista |
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