Measurement of the Effective Weak Mixing Angle in p(p)over-bar - greater than Z/gamma* - greater than e(+)e(-) Events

Abstract

We present a measurement of the fundamental parameter of the standard model, the weak mixing angle sin2θℓeff which determines the relative strength of weak and electromagnetic interactions, in pp¯→Z/γ∗→e+e− events at a center of mass energy of 1.96 TeV, using data corresponding to 9.7 fb−1 of integrated luminosity collected by the D0 detector at the Fermilab Tevatron. The effective weak mixing angle is extracted from the forward-backward charge asymmetry as a function of the invariant mass around the Z boson pole. The measured value of sin2θℓeff=0.23147±0.00047 is the most precise measurement from light quark interactions to date, with a precision close to the best LEP and SLD results.