Reparametrization Invariance and Partial Re-Summations of the Heavy Quark Expansion

TL;DR

This paper extends the concept of reparametrization invariance in the heavy-quark expansion, providing a manifestly RPI formulation of inclusive decay rates that simplifies the parameter space and partially resums higher-order terms.

Contribution

It introduces a reparametrization invariant approach to the heavy-quark expansion that reduces parameters and resums higher-order contributions.

Findings

Manifest RPI formulation of inclusive decay rates

Reduced number of independent parameters

Partial resummation of higher-order terms

Abstract

We extend existing work on reparametrization invariance (RPI) of the heavy-quark expansion. We discuss the total rates of inclusive processes and obtain results which have a manifest RPI and can be expressed through matrix elements of operators and states defined in full QCD. This approach leads to a partial re-summation of higher-order terms in the heavy-quark expansion and has the advantage that the number of independent parameters is reduced.