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

Is the total signal yield including the contribution

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Unformatted text preview: dijet invariant mass for the single- and double-tagged events in the signal region. The yields are given in Table XXXVI. The limits on Higgs production are calculated using the same procedure as for the previous two channels, and they are shown in Fig. 59. 10 Expected Limit σ(95% CL) (pb) Observed Limit 1 105 FIG. 58 (color online). The dijet invariant mass distributions for the (a) single-tagged and (b) double-tagged CDF searches in the VH ! ET bb final state. 6 Rev. Mod. Phys., Vol. 84, No. 4, October–December 2012 110 115 120 125 130 135 Higgs Mass (GeV/c2) 140 145 FIG. 59. Expected and observed 95% C.L. upper bounds on the VH production cross section for the CDF ET þ bb search. 6 Hobbs, Neubauer, and Willenbrock: Tests of the standard electroweak model at . . . 1519 TABLE XXXVII. The predicted and observed yields for the D0 VH ! ET bb analysis for the untagged control sample and the single- and 6 double-tagged analysis samples after applying the multijet BDT selection. Sample Preselection Single tagged Double tagged ZH WH W þ jets Z þ jets Top VV Multijet Total background Observed 13:73 Æ 1:37 4:16 Æ 0:42 4:66 Æ 0:58 11:64 Æ 1:17 3:60 Æ 0:37 4:00 Æ 0:50 19 069 802 191 9432 439 124 1216 404 199 1112 60 24 1196 125 <8 32025 Æ 4037 1830 Æ 255 538 Æ 87 31 718 1 712 514 b. D0 search The published D0 analysis uses a data sample correspondR ing to Ldt ¼ 5:2 fbÀ1 . Events selected for this analysis must satisfy a trigger requiring two acoplanar jets and ET in 6 which the kinematic thresholds varied as a function of the instantaneous luminosity. The primary requirements of the initial offline event preselection are at least two jets with ET > 20 GeV and jj < 2:5, Áðj1 ; j2 Þ < 165 , and ET > 6 20 GeV. This is divided into four samples: (1) a signal sample defined by the additional requirements of ET > 40 GeV, 6 S > 5, D < =2, and a veto of events with high-pT , isolated leptons; (2) an electroweak test sample enhanced in W !  events and defined similarly as for the signal sample, but requiring the presence of a high pT , isolated muon; (3) a multijet modeling sample defined similarly to the signal sample except D > =2; and (4) a multijet enriched sample used to confirm the background model predicted using the multijet modeling sample and defined by ET > 30 GeV and 6 no requirement on S. Here S is the significance of the ET and 6 D  ÁðET ; T T ¼ ET À T T Þ in which T T is the magni6~ 6~ 6 6 6 tude of the vector sum of the transverse momentum of the tracks in the event and i is the azimuthal angle of either ET or T T . 6 6 The presence of b hadrons from the H ! bb signal decay is used to improve the signal-to-noise ratio. Events were additionally required to have a least one of the two highest ET jets identified as being consistent with a b hadron jet as determined by a high purity (tight) b-jet identification requirement. Events are then categorized as double tagged if the rema...
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This document was uploaded on 09/28/2013.

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