Axial couplings of heavy hadrons from domain-wall lattice QCD

TL;DR

This paper computes axial couplings of heavy hadrons using domain-wall lattice QCD, enabling predictions of decay rates and improving chiral extrapolations in the bottom quark sector.

Contribution

It provides the first lattice QCD determination of axial couplings g_1, g_2, and g_3 for heavy hadrons with dynamical domain wall fermions.

Findings

Calculated axial couplings g_1, g_2, g_3 with two lattice spacings.

Results facilitate decay rate predictions for heavy hadrons.

Data supports chiral extrapolations down to 227 MeV pion mass.

Abstract

We calculate matrix elements of the axial current for static-light mesons and baryons in lattice QCD with dynamical domain wall fermions. We use partially quenched heavy hadron chiral perturbation theory in a finite volume to extract the axial couplings g_1, g_2, and g_3 from the data. These axial couplings allow the prediction of strong decay rates and enter chiral extrapolations of most lattice results in the b sector. Our calculations are performed with two lattice spacings and with pion masses down to 227 MeV.