Point-Split Lattice Operators for B Decays

TL;DR

This paper computes one-loop renormalizations for lattice discretizations of heavy-light bilinears used in B meson decay constant calculations, aiming to improve accuracy in lattice QCD simulations.

Contribution

It provides the first detailed calculation of one-loop renormalizations for specific heavy-light bilinear discretizations in lattice QCD.

Findings

Calculated one-loop renormalizations for heavy-light bilinear discretizations

Identified discretizations with reduced renormalization issues

Discussed applications to B meson decay constant measurements

Abstract

The matrix element which determines the B meson decay constant can be measured on the lattice using an effective field theory for heavy quarks. Various discretizations of the heavy-light bilinears which appear in this and other B decay matrix elements are possible. The heavy-light bilinear currently used for the determination of the B meson decay constant on the lattice suffers a substantial one-loop renormalization. In this paper, we compute the one-loop renormalizations of the discretizations in which the heavy and light fields in the bilinear are separated by one lattice spacing, and discuss their application. Readers of this paper may also be interested in our paper on the application of Symanzik's improvement program to heavy-light currents (paper number 9203221 on hep-ph).