Drell-Yan lepton pairs are produced in the process pp→μ+μ−+X through an intermediate γ∗/Z boson. The forward-backward asymmetry in the polar-angle distribution of the μ−as a function of the invariant mass of the μ+μ− pair is used to obtain the effective leptonic determination sin2θlepteff of the electroweak-mixing parameter sin2θW, from which the value of sin2θW is derived assuming the standard model. The measurement sample, recorded by the Collider Detector at Fermilab (CDF), corresponds to 9.2 fb−1 of integrated luminosity from pp
collisions at a center-of-momentum energy of 1.96 TeV, and is the full CDF Run II data set. The value of sin2θlepteff is found to be 0.2315 ±0.0010, where statistical and systematic uncertainties are combined in quadrature. When interpreted within the context of the standard model using the on-shell renormalization scheme, where sin2θW=1−M2W/M2Z, the measurement yields
sin2θW=0.2233±0.0009, or equivalently a W-boson mass of 80.365±0.047 GeV/c2. The value of the W-boson mass is in agreement with previous determinations in electron-positron collisions and at the Tevatron collider.