Measurement of the ratio of inclusive cross sections σ(pp̄→ Z+b-quark jet)/σ(pp̄→Z+jet) at √s=1.96TeV

The ratio of the cross section for pp interactions producing a Z boson and at least one b-quark jet to the inclusive Z+jet cross section is measured using 4.2 fb{sup -1} of pp collisions collected with the D0 detector at the Fermilab Tevatron collider at {radical}(s)=1.96 TeV. The Z{yields}l{sup +}l{sup -} candidate events with at least one b jet are discriminated from Z+charm and light jet(s) events by a novel technique that exploits the properties of the tracks associated to the jet. The measured ratio is 0.0193{+-}0.0027 for events having a jet with transverse momentum p{sub T}>20 GeV and pseudorapidity |{eta}|{<=}2.5, which is the most precise to date and is consistent with theoretical predictions.