# A Monte Carlo study of old, new and tadpole improved actions

## TL;DR

This study evaluates various improved SU(2) lattice actions, including a newly proposed one, by comparing their mass ratio scaling against analytic results, and assesses their effectiveness at different lattice spacings.

## Contribution

Introduces a new improved lattice action with a 2x2 plaquette and simplifies perturbative calculations through a covariant propagator.

## Key findings

- No further improvement observed at larger lattice spacing with tadpole correction
- Scaling results agree with analytic predictions for certain actions
- The new action provides a simplified perturbative framework

## Abstract

Scaling of mass ratios in intermediate volumes, obtained with improved SU(2) lattice actions is tested against analytic results for the Wilson and continuum action. A new improved action is introduced by adding a 2X2 plaquette to the Symanzik action. Completing a square leads to a covariant propagator that simplifies perturbative calculations. Data is presented on lattices of size 4**3X128, with lattice spacings of approximately 0.02 and 0.12 fermi. For the latter case no further improvement as compared to the tree-level action was observed when including the Lepage-Mackenzie tadpole correction to the one-loop improved Luscher-Weisz Symanzik action.