Measurement of the WW production cross section in pp̅ collisions at √s=1.96 TeV

Abstract

We present a measurement of the W boson pair-production cross section in pp̅ collisions at a center-of-mass energy of √s=1.96 TeV. The data, collected with the Run II D0 detector at Fermilab, correspond to an integrated luminosity of 224-252 pb^-1 depending on the final state (ee, eμ, or μμ). We observe 25 candidates with a background expectation of 8.1±0.6(stat)±0.6(syst)±0.5(lum) events. The probability for an upward fluctuation of the background to produce the observed signal is 2.3x10^-7, equivalent to 5.2 standard deviations. The measurement yields a cross section of 13.8_-3.8^+4.3(stat)_-0.9^+1.2(syst)±0.9(lum) pb, in agreement with predictions from the standard model.