Higgs boson search sensitivity in the H→WW dilepton decay mode at √s=7 and 10 TeV

Prospects for discovery of the standard model Higgs boson are examined at center-of-mass energies of 7 and 10 TeV at the CERN Large Hadron Collider. We perform a simulation of the signal and principal backgrounds for Higgs boson production and decay in the W⁺W^- dilepton mode, finding good agreement with the ATLAS and CMS collaboration estimates of signal significance at 14 TeV for Higgs boson masses near m_H=160GeV. At the lower energy of 7 TeV, using the same analysis cuts as these collaborations, we compute expected signal sensitivities of about 2 standard deviations (σ's) at m_H=160GeV in the ATLAS case, and about 3.6σ in the CMS case for 1fb^-1 of integrated luminosity. Integrated luminosities of 8fb^-1 and 3fb^-1 are needed in the ATLAS case at 7 and 10 TeV, respectively, for 5σ level discovery. In the CMS case, the numbers are 2fb^-1 and 1fb^-1 at 7 and 10 TeV. Our different stated expectations for the two experiments arise from the more restrictive analysis cuts in the CMS case and from the different event samples in the two cases. Recast as exclusion limits, our results show that with 1fb^-1 of integrated luminosity at 7 TeV, the LHC may be able to exclude m_H values in the range 160 to 180 GeV provided no signal is seen.