Measurement of the b quark forward-backward asymmetry around the Z0 peak using an inclusive tag

TL;DR

This paper reports a measurement of the b quark forward-backward asymmetry around the Z0 peak using an inclusive tagging method, providing insights into electroweak parameters within the Standard Model.

Contribution

It introduces an inclusive tagging technique combining jet, vertex, and kaon charges to measure the asymmetry at different energies around the Z0 peak.

Findings

Measured asymmetry values at three energies with statistical and systematic errors.

Derived the effective weak mixing angle, sin^2θ_W^eff,e = 0.23205 ± 0.00068.

Results are consistent with Standard Model predictions.

Abstract

The b quark forward-backward asymmetry has been measured using hadronic Z0 decays collected by the OPAL experiment at LEP. Z0 -> bbbar decays were selected using a combination of secondary vertex and lepton tags, and the sign of the b quark charge was determined using an inclusive tag based on jet, vertex and kaon charges. The results, corrected to the quark level, are: A^b_FB = 0.0582 +- 0.0153 +- 0.0012 at sqrt(s) = 89.50 GeV A^b_FB = 0.0977 +- 0.0036 +- 0.0018 at sqrt(s) = 91.26 GeV A^b_FB = 0.1221 +- 0.0123 +- 0.0025 at sqrt(s) = 92.91 GeV where the first error is statistical and the second systematic in each case. Within the framework of the Standard Model, the result is interpreted as a measurement of the effective weak mixing angle for electrons of sin2theta_W^eff,e = 0.23205 +- 0.00068.