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

Abstract

The ratio of the cross section for pp̅ 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^-1 of pp̅ collisions collected with the D0 detector at the Fermilab Tevatron collider at √s=1.96 TeV. The Z→l⁺l^- 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_τ>20 GeV and pseudorapidity |η|≤2.5, which is the most precise to date and is consistent with theoretical predictions.