Search for the Higgs boson in the $H \to WW \to l\nu jj$ decay channel in $pp$ collisions at $\sqrt{s}$ = 7 TeV with the ATLAS detector

A search for a Higgs boson has been performed in the $H \to WW \to l\nu jj$ channel using 1.04 $fb^{-1}$ of $pp$ collision data at $\sqrt{s}$ = 7 TeV recorded with the ATLAS detector at the Large Hadron Collider. No significant excess of events is observed over the expected Standard Model (SM) background and limits on the Higgs boson production cross section are derived for a Higgs boson mass in the range 240 GeV $\lt mH \lt$ 600 GeV. The best sensitivity is obtained for mH = 400 GeV, where the 95% confidence level upper bound on the cross section for $H \to WW$ production is 3.1 pb, or 2.7 times the Standard Model prediction.