First measurement of W Boson production in association with a single charm quark in pp collisions at s=1.96 TeV

The authors present the first measurement of the production cross section of a W boson with a single charm quark(c) in p{bar p} collisions at {radical}s = 1.96 TeV, using soft muontagging of c jets. In a data sample of {approx} 1.8 fb{sup -1}, recorded with the CDF II detector at the Fermilab Tevatron, they select events with W + 1 or 2 jets. They use the charge correlation between the W and the muonfrom the semileptonic decayof a charm hadron to extract the We signal. They measure {sigma}{sub Wc} (p{sub Tc} > 20 GeV/c, |{eta}{sub c}| < 1.5) x BR(W {yields} {ell}{nu}) = 9.8 {+-} 3.2 pb, in agreement with theoretical expectations.