Applications of the Perturbative Gradient Flow

TL;DR

This paper explores the perturbative gradient flow formalism in lattice QCD, demonstrating its potential for calculating vacuum expectation values and vacuum polarization functions to improve parameter extraction and theoretical evaluations.

Contribution

It introduces a perturbative approach to gradient flow, applying it to compute flowed operator expectation values and to the operator product expansion for lattice QCD.

Findings

Computed vacuum expectation values of flowed operators.

Applied flowed operator product expansion to current correlators.

Proposed methods for extracting physical parameters from lattice data.

Abstract

Over the last decade the gradient flow formalism became an important tool for lattice simulations of Quantum Chromodynamics. It offers remarkable renormalization properties which pave the way for cross-fertilization between perturbative and lattice calculations. In this contribution we discuss the perturbative approach. As first application we compute vacuum expectation values of flowed operators which could help to extract parameters like the strong coupling constant from lattice simulations. Afterwards, we apply the flowed operator product expansion to the time-ordered product of two currents which could be employed for an alternative first-principle evaluation of vacuum polarization functions on the lattice.