Measurement of the t t ˉ production cross section using dilepton events in p p ˉ collisions

摘要

We present a measurement of the t t ˉ production cross section σ t t ˉ in p p ˉ collisions at s = 1.96 TeV using 5.4 ? fb ? 1 of integrated luminosity collected with the D0 detector. We consider final states with at least two jets and two leptons ( ee , eμ , μμ ), and events with one jet for the eμ final state as well. The measured cross section is σ t t ˉ = 7.36 ? 0.79 + 0.90 ( stat + syst ) ? pb . This result combined with the cross section measurement in the lepton + jets final state yields σ t t ˉ = 7.56 ? 0.56 + 0.63 ( stat + syst ) ? pb , which agrees with the standard model expectation. The relative precision of 8% of this measurement is comparable to the precision of the latest theoretical calculations.