Searching for the Heavy Higgs Boson at Lhc in the Higgs Boson Going to W Boson W Boson Going to Lepton Neutrino Jet Jet Decay Mode.

The discovery of the Higgs boson with mass up to m_{H} = 1 TeV at the Large Hadron Collider is possible in the Hto WWto lvjj decay mode. The expected event rate after cuts for an integrated luminosity of 100 fb ^{-1} is of the order of 100 events for the Higgs signal, with a combined background that is a factor of two smaller. For the Higgs boson to be discovered in this decay mode, the combined use of double jet tagging, additional central jet vetoing and the reconstruction of the W to jj invariant mass is needed. This result is obtained by a complete leading order parton level calculation of Wiggs plus 2 jets cross section, and of the two most important backgrounds, W + jets and toverline{t} production. In addition, the tree level { cal O}(alpha_{s}) corrections to both the signal and the background cross sections are presented. These calculations show that the traditional hadron level rapidity gap trigger will not be feasible for heavy Higgs searches at the LHC. The alternative of defining the rapidity gap in terms of minijets is studied in detail, and it is found to be a possible strategy for isolating the Higgs signal from background, provided that the background from overlapping minimum bias events can be independently eliminated.