Higher Loop Results for the Plaquette, Using the Clover and Overlap Actions

TL;DR

This paper computes higher-loop perturbative corrections to the lattice QCD free energy, focusing on the plaquette, using clover and overlap actions across various parameters.

Contribution

It provides the first three-loop results for the plaquette with clover fermions and two-loop results with overlap fermions, covering arbitrary clover coefficients and fermion masses.

Findings

Three-loop perturbative value for the plaquette with clover action.

Two-loop perturbative value for the plaquette with overlap action.

Results applicable to a wide range of fermion masses and clover coefficients.

Abstract

We calculate the perturbative value of the free energy in QCD on the lattice. This quantity is directly related to the average plaquette. Our calculation is done to 3 loops using the clover action for fermions; the results are presented for arbitrary values of the clover coefficient, and for a wide range of fermion masses. In addition, we calculate the 2 loop result for the same quantity, using the overlap action.