Search for the Standard Model Higgs boson produced in association with a vector boson and decaying to a b-quark pair with the ATLAS detector

This Letter presents the results of a direct search with the ATLAS detector at the LHC for a Standard Model Higgs boson of mass 110⩽mH⩽130GeV produced in association with a W or Z boson and decaying to bb¯. Three decay channels are considered: ZH→ℓ+ℓ−bb¯, WH→ℓνbb¯ and ZH→νν¯bb¯, where ℓ corresponds to an electron or a muon. No evidence for Higgs boson production is observed in a dataset of 7TeVpp collisions corresponding to 4.7fb−1 of integrated luminosity collected by ATLAS in 2011. Exclusion limits on Higgs boson production, at the 95% confidence level, of 2.5 to 5.5 times the Standard Model cross section are obtained in the mass range 110-130GeV. The expected exclusion limits range between 2.5 and 4.9 for the same mass interval.