We compute two quantities that are used in this report and that have been traditionally used for further elaborations and tests involving the τ branching fractions:
Following Ref. [77], we obtain a more precise experimental determination of B e using the τ branching fraction to µ ν ν, B µ, and the τ lifetime. We average:
Accounting for statistical correlations, we obtain
|
We use B euni to obtain the ratio
|
where Γ(τ → hadrons) and Γ(τ→ eνν) indicate the partial widths and Γhadrons is the total branching fraction of the τ to hadrons, or the total branching fraction in any measured final state minus the leptonic branching fractions, i.e., with our notation Γhadrons = ΓAll − Γ3 − Γ5 = (64.76 ± 0.10)% (see Section 2 and Table 1 for the definitions of ΓAll, Γ3, Γ5). We underline that this report’s definition of Γhadrons corresponds to summing all τ hadronic decay modes, like in the previous report, rather than – as done elsewhere – subtracting the leptonic branching fractions from unity, i.e., Γhadrons = 1 − Γ3 − Γ5.