Search for a standard model-like Higgs boson in the μ+μ- and e+e- decay channels at the LHC

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 (View the MathML source) 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.