Averages of $b$-hadron, $c$-hadron, and $\tau$-lepton properties as of 2018

TL;DR

This paper provides comprehensive world averages of properties related to $b$-hadron, $c$-hadron, and $ au$-lepton particles, consolidating measurements up to September 2018 to support particle physics research.

Contribution

It presents the first unified set of averages for these particles' properties, incorporating recent measurements and standardized analysis methods.

Findings

Updated averages for branching fractions and lifetimes

Precise measurements of meson mixing and CP violation

Refined CKM matrix element values

Abstract

This paper reports world averages of measurements of $b$-hadron, $c$-hadron, and $\tau$-lepton properties obtained by the Heavy Flavor Averaging Group using results available through September 2018. In rare cases, significant results obtained several months later are also used. For the averaging, common input parameters used in the various analyses are adjusted (rescaled) to common values, and known correlations are taken into account. The averages include branching fractions, lifetimes, neutral meson mixing parameters, CP violation parameters, parameters of semileptonic decays, and Cabibbo-Kobayashi-Maskawa matrix elements.