1. HET/ATLAS JOINT LUNCH SEMINAR

    "Search for new light gauge bosons in Higgs boson decays to four-lepton final states in pp collisions at sqrt(s) = 8 TeV with the ATLAS detector at the LHC"

    Presented by Ketevi Assamagan, BNL

    Friday, May 29, 2015, 12 pm
    Building 510 Room 2-160

    Hosted by: Amarjit Soni

    "A search for Higgs bosons decays to four leptons via one or two light exotic vector bosons, Zdark, H -> Z Zdark -> 4l and H -> Zdark Zdark -> 4l (l=electron or muon), is presented. The search is performed using proton-proton collision data corresponding to an integrated luminosity of about 20/fb at the center-of-mass energy of 8 TeV recorded with the ATLAS detector at the Large Hadron Collider. The observed data are well described by the Standard Model prediction. Upper bounds at 95% confidence level are set on the relative branching ratios BR(H -> ZZdark -> 4l to BR(H -> 4l for the exotic vector boson masses between 15 and 55 GeV, and on BR(H -> Zdark Zdark -> 4l to BR(H -> ZZ^* -> 4l for the exotic vector boson masses between 15 and 60 GeV. The results are interpreted in benchmark models where a dark gauge symmetry is mediated by a dark vector boson."