A search is presented for a standard model-like Higgs boson decaying to the μ+μ− or e+e− final states based on proton–proton collisions recorded by the CMS experiment at the CERN LHC. The data correspond to integrated luminosities of 5.0 fb−1 at a centre-of-mass energy of 7 TeV and 19.7 fb−1 at 8 TeV for the μ+μ− search, and of 19.7 fb−1 at 8 TeV for the e+e− search. Upper limits on the production cross section times branching fraction at the 95% confidence level are reported for Higgs boson masses in the range from 120 to 150 GeV. For a Higgs boson with a mass of 125 GeV decaying to μ+μ−, the observed (expected) upper limit on the production rate is found to be 7.4 (6.5−1.9+2.8) times the standard model value. This corresponds to an upper limit on the branching fraction of 0.0016. Similarly, for e+e−, an upper limit of 0.0019 is placed on the branching fraction, which is ≈3.7×105 times the standard model value. These results, together with recent evidence of the 125 GeV boson coupling to τ-leptons with a larger branching fraction consistent with the standard model, confirm that the leptonic couplings of the new boson are not flavour-universal.
Khachatryan, V., Sirunyan, A., Tumasyan, A., Adam, W., Bergauer, T., Dragicevic, M., et al. (2015). Search for a standard model-like Higgs boson in the μ+μ− and e+e− decay channels at the LHC. PHYSICS LETTERS. SECTION B, 744, 184-207 [10.1016/j.physletb.2015.03.048].
Search for a standard model-like Higgs boson in the μ+μ− and e+e− decay channels at the LHC
DINARDO, MAURO EMANUELEPrimo
Membro del Collaboration Group
;FIORENDI, SARASecondo
Membro del Collaboration Group
;GEROSA, RAFFAELE ANGELOMembro del Collaboration Group
;GHEZZI, ALESSIOMembro del Collaboration Group
;GOVONI, PIETROMembro del Collaboration Group
;LUCCHINI, MARCO TOLIMANMembro del Collaboration Group
;MANZONI, RICCARDO ANDREAMembro del Collaboration Group
;MARTELLI, ARABELLAMembro del Collaboration Group
;MARZOCCHI, BADDERMembro del Collaboration Group
;MORONI, LUIGIMembro del Collaboration Group
;PAGANONI, MARCOMembro del Collaboration Group
;RAGAZZI, STEFANOMembro del Collaboration Group
;TABARELLI DE FATIS, TOMMASOUltimo
Membro del Collaboration Group
;Branca, A.;De Guio, F.Membro del Collaboration Group
;
2015
Abstract
A search is presented for a standard model-like Higgs boson decaying to the μ+μ− or e+e− final states based on proton–proton collisions recorded by the CMS experiment at the CERN LHC. The data correspond to integrated luminosities of 5.0 fb−1 at a centre-of-mass energy of 7 TeV and 19.7 fb−1 at 8 TeV for the μ+μ− search, and of 19.7 fb−1 at 8 TeV for the e+e− search. Upper limits on the production cross section times branching fraction at the 95% confidence level are reported for Higgs boson masses in the range from 120 to 150 GeV. For a Higgs boson with a mass of 125 GeV decaying to μ+μ−, the observed (expected) upper limit on the production rate is found to be 7.4 (6.5−1.9+2.8) times the standard model value. This corresponds to an upper limit on the branching fraction of 0.0016. Similarly, for e+e−, an upper limit of 0.0019 is placed on the branching fraction, which is ≈3.7×105 times the standard model value. These results, together with recent evidence of the 125 GeV boson coupling to τ-leptons with a larger branching fraction consistent with the standard model, confirm that the leptonic couplings of the new boson are not flavour-universal.
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