RevModPhys.84.1477】Tests of the standard electroweak model at the energy frontier

Production tt single top diboson production ww wz and

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Unformatted text preview: 8 439 349 283 45.7 38.6 33.6 28.6 0.682 0.901 0.965 0.934 Sec. V.B.5. A combination of these results is described in Sec. V.C. The following sections describe the individual channels used in the Higgs search starting with the low mass channels WH ! ‘bb, ZH ! ‘‘bb, ZH ! bb, and  final states, and finishing with the high mass H ! WW ðÃÞ ! ‘‘ search. The Higgs-boson section concludes with a presentation of the most recent set of CDF and D0 combined limits. 1. WH ! ‘bb final state Rev. Mod. Phys., Vol. 84, No. 4, October–December 2012 Hobbs, Neubauer, and Willenbrock: Tests of the standard electroweak model at . . . 1514 TABLE XXX. The neural network inputs for the CDF and D0 WH analyses. Here Ji denotes the ith jet in a list ordered by jet ET min in which J1 is the highest ET jet in the event. M‘j is the mass of the lepton, ET , and the jet (J1 or J2 ) which gives the lower mass value. 6 Finally, max is the three momentum of the neutrino in which jpZ j is the larger of the two values calculated when forcing the lepton and neutrino system to have a mass equal to the W boson mass. CDF D0 MJJþ invariant mass of J1 and J2 and the closest loose jet if ÁRðJ; Jloose Þ < 0:9 ÆET (loose jets) pT ðJ1 Þ þ pT ðJ2 Þ þ pT ð‘Þ À ET 6 min M‘j ÁRð‘; max Þ ~ ~ ~ ~ jpT ð‘Þ þ pT ð6ET Þ þ pT ðJ1 Þ þ pT ðJ2 Þj MJJ invariant mass of J1 and J2 ET ðJ1 Þ ET ðJ2 Þ ÁRðJ1 ; J2 Þ ÁðJ1 ; J2Þ ~ ~ jpT ð‘Þ þ pT ð6ET Þj ~ jpT ðJ1 Þ þ pT ðJ2 Þj ~ based on comparison of data and simulated control samples. The W þ jets background cross sections are poorly known, and data-driven approaches are used to estimate these yields. The multijet background is hard to model from simulation, so data-driven methods are also used for this background. The two experiments use different data-driven methods as outlined below. The total W þ jets background after b tagging in the CDF result is estimated separately for W þ lf events and W þ hf events. The W þ lf contribution is estimated by applying data-derived mistag probabilities to untagged W þ jets samples. Three different tagging algorithms are used in the analysis, and the mistag probability determination differs for each of these. For the SECVTX and JP tagging algorithms, the mistag probability (Acosta et al., 2005e; Abulencia et al., 2006b) is derived using events with a negative decay length with a correction applied to account for the heavy-flavor content of the control sample used to determine the mistag probability. For the JP algorithm, the mistag probability is parametrized as a function of , primary vertex z position, jet ET , scalar transverse energy, and vertex and track multiplicity. For the NN-based tagging algorithm, a light-flavor rejection factor derived from control data samples is used. The TABLE XXXI. (2009g). W þ hf contribution is determined by measuring the heavyflavor faction in W þ jets events and applying a b-tagging effici...
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