Automated generation of lattice QCD Feynman rules

TL;DR

This paper presents software that automates the complex process of deriving Feynman rules in lattice QCD, accommodating highly improved actions like HISQ and NRQCD, thus streamlining theoretical calculations.

Contribution

The authors develop a versatile software suite capable of generating and evaluating Feynman rules for complex lattice actions, including automated differentiation of diagrams.

Findings

Successfully handles complex actions like HISQ and NRQCD

Automates derivation and evaluation of Feynman rules

Enhances efficiency in lattice QCD perturbation theory

Abstract

The derivation of the Feynman rules for lattice perturbation theory from actions and operators is complicated, especially for highly improved actions such as HISQ. This task is, however, both important and particularly suitable for automation. We describe a suite of software to generate and evaluate Feynman rules for a wide range of lattice field theories with gluons and (relativistic and/or heavy) quarks. Our programs are capable of dealing with actions as complicated as (m)NRQCD and HISQ. Automated differentiation methods are used to calculate also the derivatives of Feynman diagrams.