Hadron correlators with improved fermions

TL;DR

This paper studies mesonic and baryonic correlators using improved Wilson fermions, revealing enhanced discretisation effects but confirming phenomenological predictions about correlator ratios and binding at the chiral limit.

Contribution

It provides a detailed analysis of point-to-point correlators with ${ m O}(a)$-improved Wilson fermions, highlighting discretisation effects and confirming phenomenological features.

Findings

Discretisation effects are more pronounced with improved Wilson fermions.

The ratio of interacting to free correlators remains roughly constant in the vector channel up to 1 fm.

In the pseudoscalar channel, the ratio increases significantly due to strong binding.

Abstract

We investigate point-to-point correlation functions for various mesonic and baryonic channels using the ${\cal O}(a)$-improved Wilson action due to Sheikholeslami and Wohlert. We consider propagators to both time slices 0 and 1. We find that discretisation effects are more pronounced than those reported with unimproved Wilson fermions, but that the same procedure for removing finite size effects is successful. Extrapolating to the chiral limit, we see the notable features predicted phenomenologically: the ratio of interacting to free correlators in the vector channel is roughly constant to about 1 fm, while in the pseudoscalar channel the ratio increases markedly due to the strong binding.