H→WW as the discovery mode for a light Higgs boson

The production cross section for a mH≈115 GeV, SM Higgs boson in weak boson fusion at the LHC is sizable. However, the branching fraction for H→W+W− is expected to be relatively small. The signal, with its two forward jets, is sufficiently different from the main backgrounds that a signal to background ratio of better than 1:1 can nevertheless be obtained, with large enough rate to allow for a 5σ signal with 35 fb−1 of data. The H→WW signal in weak boson fusion may thus prove to be the discovery mode for the Higgs boson at the LHC.