Single-forward-jet tagging and central-jet vetoing to identify the leptonic WW decay mode of a heavy Higgs boson.

Abstract

We study the extraction of the heavy-Higgs-boson signal $H\ensuremath{\rightarrow}{W}^{+}{W}^{\ensuremath{-}}\ensuremath{\rightarrow}\overline{\ensuremath{\ell}}\ensuremath{\nu}, \ensuremath{\ell}\overline{\ensuremath{\nu}}$ ($\ensuremath{\ell}=e or \ensuremath{\mu}$) from the standard-model background at hadron supercolliders. By tagging a single forward jet with energy ${E}_{j}>3$ TeV and pseudorapidity $3<|{\ensuremath{\eta}}_{j}|<5$ and by vetoing central jets of transverse momenta ${p}_{\mathrm{Tj}}>60$ GeV in the pseudorapidity range $0<|{\ensuremath{\eta}}_{j}|<3$, the QCD $\mathrm{WWj}$ and $t\overline{t}j\ensuremath{\rightarrow}\mathrm{WWb}\overline{b}j$ backgrounds are suppressed. For ${m}_{H}=1$ TeV there are about 46 signal events from electroweak-vector-boson scattering (of which 36 events are of Higgs-boson origin) at the Superconducting Super Collider (SSC) for an integrated luminosity of 10 ${\mathrm{fb}}^{\ensuremath{-}1}$ and 10 other events from the $\mathrm{WWj}$ and $t\overline{t}j$ backgrounds for ${m}_{t}=140$ GeV. The experimental separation of the vector-boson-scattering subprocess is thereby possible. At the CERN Large Hadron Collider, with an ${E}_{j}>2$ TeV jet energy cut, all cross sections are about a factor of 10 below the SSC values.