AION/Magis

Abstract:

A search for a narrow Higgs boson resonance in the diphoton mass spectrum is presented based on data corresponding to 10fb -1 of integrated luminosity collected by the CDF experiment from proton-antiproton collisions at s=1.96TeV. To increase the sensitivity of the search, we employ a multivariate discriminant technique for the first time in this channel at CDF. No evidence of signal is observed, and upper limits are set on the cross section times branching ratio of the resonant state as a function of the Higgs boson mass. The limits are interpreted in the context of the standard model with an expected (observed) limit on the cross section times branching ratio of 9.9 (17.0) times the standard model prediction at the 95% credibility level for a Higgs boson mass of 125GeV/c 2. Moreover, a Higgs boson with suppressed couplings to fermions is excluded for masses below 114GeV/c 2 at the 95% credibility level. © 2012 Elsevier B.V.

Abstract:

A search is performed for heavy Majorana neutrinos (N) using an event signature defined by two same-sign charged leptons of the same flavour and two jets. The data correspond to an integrated luminosity of 4.98fb-1 of pp collisions at a centre-of-mass energy of 7 TeV collected with the CMS detector at the Large Hadron Collider. No excess of events is observed beyond the expected standard model background and therefore upper limits are set on the square of the mixing parameter, |VℓN|2, for ℓ=e, μ, as a function of heavy Majorana-neutrino mass. These are the first direct upper limits on the heavy Majorana-neutrino mixing for mN>90GeV. © 2012 CERN.