HQET with chiral symmetry on the lattice

TL;DR

This paper introduces a lattice QCD approach combining static heavy quarks with Neuberger light quarks, simplifying operator renormalization by reducing it to a few constants, and computes these constants at NLO.

Contribution

It presents a novel method that simplifies the renormalization process for heavy-light operators in lattice QCD using chiral symmetry.

Findings

Renormalization of heavy-light bilinears is reduced to a single constant.

Four-quark operators' renormalization involves only four constants.

Matching constants are computed at next-to-leading order in perturbation theory.

Abstract

We show that by combining the static heavy quark action with the Neuberger action for the light quark, the renormalisation of the heavy-light bilinear and four-quark operators, computed on the lattice, becomes highly simplified: all the heavy-light bilinears get renormalised by a single multiplicative constant, whereas the renormalisation of the complete set of parity even dB=2 four-quark operators involves only four independent constants. The relevant (matching) constants are computed at NLO in perturbation theory and are presented here.