Measurement of the Branching Ratio for the Process b -> tau nu X

TL;DR

This paper reports a measurement of the inclusive branching ratio for b quark decays to tau neutrinos, using data from the OPAL experiment, providing insights consistent with the Standard Model and constraining new physics models.

Contribution

First measurement of the inclusive b -> tau nu X branching ratio using LEP data, constraining parameters of Two Higgs Doublet Models.

Findings

BR(b -> tau nu X) = (2.78 +/- 0.18 +/- 0.51)%

Measurement consistent with Standard Model

Sets limits on Two Higgs Doublet Model parameters

Abstract

The inclusive branching ratio for the process b -> tau nu X has been measured using hadronic Z decays collected by the OPAL experiment at LEP in the years 1992-2000. The result is: BR(b -> tau nu X) = (2.78 +/- 0.18 +/- 0.51)% This measurement is consistent with the Standard Model expectation and puts a constraint of tan(beta) / M(H+/-) < 0.53 GeV-1 at the 95% confidence level on Type II Two Higgs Doublet Models.