Measurement of B(t->Wb)/B(t->Wq) at the Collider Detector at Fermilab

TL;DR

This paper measures the ratio of top-quark decay modes to b quarks versus all down-type quarks using Tevatron data, providing insights into the top quark's decay properties and testing the Standard Model.

Contribution

First measurement of the top-quark branching ratio to Wb relative to all Wq decays using secondary vertex identification at Fermilab.

Findings

Lower limit of R > 0.61 at 95% confidence level.

Consistent with Standard Model predictions.

Utilized lepton-plus-jets and dilepton data sets.

Abstract

We present a measurement of the ratio of top-quark branching fractions R= B(t -> Wb)/B(t -> Wq), where q can be a b, s or a d quark, using lepton-plus-jets and dilepton data sets with integrated luminosity of ~162 pb^{-1} collected with the Collider Detector at Fermilab during Run II of the Tevatron. The measurement is derived from the relative numbers of t-tbar events with different multiplicity of identified secondary vertices. We set a lower limit of R > 0.61 at 95% confidence level.