Measurement of σ(pp¯→Z+X)Br(Z→τ+τ−) at s=1.96 TeV

Abstract We present a measurement of the cross section for Z boson production times the branching fraction to tau lepton pairs σ ( p p ¯ → Z + X ) Br ( Z → τ + τ − ) in p p ¯ collisions at s = 1.96 TeV . The measurement is performed in the channel in which one tau lepton decays into a muon and neutrinos, and the other tau lepton decays hadronically or into an electron and neutrinos. The data sample corresponds to an integrated luminosity of 1.0 fb −1 collected with the DO detector at the Fermilab Tevatron Collider. The sample contains 1511 candidate events with an estimated 20% background from jets or muons misidentified as tau leptons. We obtain σ ⋅ Br = 240 ± 8 ( stat ) ± 12 ( sys ) ± 15 ( lum ) pb , which is consistent with the standard model prediction.