We present a search for associated production of Higgs and W bosons in p (p) over bar collisions at a center of mass energy of sqrt(s) = 1.96 TeV in 5.3 fb(-1) of integrated luminosity recorded by the DO experiment. Multivariate analysis techniques are applied to events containing one lepton, an imbalance in transverse energy, and one or two b-tagged jets to discriminate a potential WH signal from Standard Model backgrounds.
We observe good agreement between data and expected backgrounds, and set an upper limit of 4.5 (at 95% confidence level and for m(H) = 115 GeV) on the ratio of the WH cross section multiplied by the branching fraction of H -} b (b) over bar to its Standard Model prediction, which is consistent with an expected limit of 4.8.