Measurement of σ(pp̅ →Z)·Br(Z→TT) at √s=1.96 TeV

Abstract

We present a measurement of the cross section for Z production times the branching fraction to t leptons, σ·Br(Z→t⁺t^-), in pp¯ collisions at √s=1.96 TeV in the channel in which one τ decays into μν_μν_τ, and the other into hadrons+ν_τ or eν_eν_t. The data sample corresponds to an integrated luminosity of 226 pb^-1 collected with the D∅ detector at the Fermilab Tevatron collider. The final sample contains 2008 candidate events with an estimated background of 55%. From this we obtain σ·Br(Z→τ⁺τ^-)=237±15(stat)±18(sys)±15(lum)pb, in agreement with the standard model prediction.