Search for a Standard Model Higgs Boson in the Decay H→WW→lνlν with 200 pb−1 at ATLAS

The prospects for Higgs boson searches using the H→WW(⁎)→lνlν (l=e,μ) decay mode at ATLAS for a proton-proton centre-of-mass energy of 10 TeV are presented. Events are separated into three categories depending on the hadronic jet multiplicity. Methods to estimate the main backgrounds from the data and systematic uncertainties are discussed. The sensitivity of the ATLAS detector is reported assuming a data set of an integrated luminosity of 200 pb−1. Under these conditions it is possible to exclude a Standard Model Higgs boson with a mass in the range 160-170 GeV at the 95% Confidence Level.