Indirect measurement of sin2θW (or MW) using μ+μ- pairs from γ* /Z bosons produced in p p ̄ collisions at a center-of-momentum energy of 1.96 TeV INDIRECT MEASUREMENT of sin2θW (OR ... T. AALTONEN et al.

Drell-Yan lepton pairs are produced in the process $p\overline{p}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}+X$ through an intermediate ${\ensuremath{\gamma}}^{*}/Z$boson. The forward-backward asymmetry in the polar-angle distribution of the ${\ensuremath{\mu}}^{\ensuremath{-}}$ as a function of the invariant mass of the ${\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ pair is used to obtain the effective leptonic determination ${\mathrm{sin}}^{2}{\ensuremath{\theta}}_{\text{eff}}^{\text{lept}}$ of the electroweak-mixing parameter ${\mathrm{sin}}^{2}{\ensuremath{\theta}}_{W}$, from which the value of ${\mathrm{sin}}^{2}{\ensuremath{\theta}}_{W}$ is derived assuming the standard model. The measurement sample, recorded by the Collider Detector at Fermilab (CDF), corresponds to $9.2\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of integrated luminosity from $p\overline{p}$ collisions at a center-of-momentum energy of 1.96 TeV, and is the full CDF Run II data set. The value of ${\mathrm{sin}}^{2}{\ensuremath{\theta}}_{\text{eff}}^{\text{lept}}$ is found to be $0.2315\ifmmode\pm\else\textpm\fi{}0.0010$, 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 ${\mathrm{sin}}^{2}{\ensuremath{\theta}}_{W}=1\ensuremath{-}{M}_{W}^{2}/{M}_{Z}^{2}$, the measurement yields ${\mathrm{sin}}^{2}{\ensuremath{\theta}}_{W}=0.2233\ifmmode\pm\else\textpm\fi{}0.0009$, or equivalently a $W$-boson mass of $80.365\ifmmode\pm\else\textpm\fi{}0.047\text{ }\text{ }\mathrm{GeV}/{c}^{2}$. The value of the $W$-boson mass is in agreement with previous determinations in electron-positron collisions and at the Tevatron collider.