Tevatron Run II combination of the effective leptonic electroweak mixing angle

Understand

Drell-Yan lepton pairs produced in the process $p \bar{p} \rightarrow \ell^+\ell^- + X$ through an intermediate $\gamma^*/Z$ boson have an asymmetry in their angular distribution related to the spontaneous symmetry breaking of the electroweak force and the associated mixing of its neutral gauge bosons.

• The CDF and D0 experiments have measured the effective-leptonic electroweak mixing parameter $\sin^2\theta^{\rm lept}_{\rm eff}$ using electron and muon pairs selected from the full Tevatron proton-antiproton data sets collected in 2001-2011, corresponding to 9-10 fb$^{-1}$ of integrated luminosity.
• The combination of these measurements yields the most precise result from hadron colliders, $\sin^2 \theta^{\rm lept}_{\rm eff} = 0.23148 \pm 0.00033$.
• This result is consistent with, and approaches in precision, the best measurements from electron-positron colliders.