Measurements of $A_{LR}$, $A_{lepton}$ and $A_{b}$ from SLD

TL;DR

This paper reports measurements of leptonic and bottom quark asymmetries from the SLD experiment, providing a precise determination of the weak mixing angle and new insights into electroweak interactions.

Contribution

It presents the first comprehensive set of asymmetry measurements from SLD, including $A_{LR}$, $A_{lepton}$, and $A_b$, with improved precision and combined results.

Findings

Effective weak mixing angle: ${ m sin}^2{ heta}_W^{eff} = 0.23109 \, extpm \, 0.00029

Measured $A_b$ value: 0.866 \, extpm \, 0.036

Consistent results with Standard Model predictions

Abstract

We present the measurements of the leptonic asymmetries in $Z^0$ decays measured by the SLD experiment at SLAC. A data sample of approximately 550,000 $Z^0$ bosons are used for the preliminary measurement of $A_{LR}(A_{e})$ and the leptonic final state measurements of $A_{e}$, $A_{\mu}$ and $A_{\tau}$, representing the entire set of 1992-1998 SLD runs. When combining all results, a preliminary value for the effective weak mixing angle is obtained: ${\sin}^2{\theta}_{W}^{eff} = 0.23109 \pm 0.00029$. We also present the direct measurements of $A_{b}$ from left-right forward-backward asymmetries, using partial data samples from 1993-1998 SLD runs. The preliminary value combines jet charge, cascade kaon and semileptonic decay analyses to obtain $A_{b} = 0.866 \pm 0.036$.