Searching for a heavy Higgs boson via the H ! l jjdecay mode at the CERN

The discovery of a heavy Higgs boson with mass up to m H = 1 TeV at the CERN LHC is possible in the H ! W + W ? ! ljj decay mode. The weak boson scattering signal and backgrounds from t tjj and from W+jets production are analyzed with parton level Monte Carlo programs which are built on full tree level amplitudes for all subprocesses. The use of double jet tagging and the reconstruction of the W invariant mass reduce the combined backgrounds to the same level as the Higgs signal. A central mini-jet veto, which distinguishes the diierent gluon radiation patterns of the hard processes, further improves the signal to background ratio to about 2.5:1, with a signal cross section of 1 fb. The jet energy asymmetry of the W ! jj decay will give a clear signature of the longitudinal polarization of the Ws in the nal event sample.