# Effect of Improving the Lattice Gauge Action on QCD Topology

## TL;DR

This paper investigates how improving the lattice gauge action in QCD reduces artificial renormalizations of topological susceptibility, by comparing different actions and methods for measuring topological charges on the lattice.

## Contribution

It demonstrates that using improved actions approaching the renormalization trajectory enhances the correlation between various topological charge measurements, reducing artifacts.

## Key findings

- Improved actions increase correlation between topological charge methods.
- Approaching the renormalization trajectory suppresses lattice artifacts.
- Different topological charge measurement methods become more consistent.

## Abstract

We use lattice topology as a laboratory to compare the Wilson action (WA) with the Symanzik-Weisz (SW) action constructed from a combination of (1x1) and (1x2) Wilson loops, and the estimate of the renormalization trajectory (RT) from a renormalization group transformation (RGT) which also includes higher representations of the (1x1) loop. Topological charges are computed using the geometric (L\"uscher's) and plaquette methods on the uncooled lattice, and also by using cooling to remove ultraviolet artifacts. We show that as the action improves by approaching the RT, the topological charges for individual configurations computed using these three methods become more highly correlated, suggesting that artificial lattice renormalizations to the topological susceptibility can be suppressed by improving the action.