Heavy quark expansion parameters from lattice NRQCD

TL;DR

This paper calculates heavy quark expansion parameters for mesons and baryons using lattice NRQCD, providing consistent results through two methods and discussing implications for particle lifetime ratios.

Contribution

It introduces a lattice NRQCD approach to determine heavy quark expansion parameters, validating two calculation methods and exploring their impact on lifetime ratios.

Findings

Consistent values of $_{}^2$ and $_G^2$ from two methods.

Application to heavy hadron lifetime ratios.

Results obtained on a quenched lattice at $eta=6.0$.

Abstract

We present a lattice QCD calculation of the heavy quark expansion parameters $\mu_{\pi}^2$ and $\mu_G^2$ for heavy-light mesons and heavy-light-light baryons. The calculation is carried out on a 20$^3\times$48 lattice at $\beta$ = 6.0 in the quenched approximation, using the lattice NRQCD action for heavy quarks. We obtain the parameters $\mu_{\pi}^2$ and $\mu_G^2$ in two different methods: a direct calculation of the matrix elements and an indirect calculation through the mass spectrum, and confirm that the both methods give consistent results. We also discuss an application to the lifetime ratios.