Measurement of the tt̄ production cross section in pp collisions at √s = 7 TeV in dilepton final states containing a 𝜏

Abstract

The top quark pair production cross section is measured in dilepton events with one electron or muon, and one hadronically decaying τ lepton from the decay tt̄ → (ℓν_ℓ), (τ_h ν_τ)bb̄, (ℓ = e, μ). The data sample corresponds to an integrated luminosity of 2.0 fb⁻¹ for the electron channel and 2.2 fb⁻¹ for the muon channel, collected by the CMS detector at the LHC. This is the first measurement of the tt̄ cross section explicitly including τ leptons in proton-proton collisions at √s = 7 TeV. The measured value σ_tt̄ = 143 ± 14(stat) ± 22(syst) ± 3(lumi) pb is consistent with the standard model predictions.