Luescher-Weisz algorithm for excited states of the QCD flux-tube

TL;DR

This paper introduces an improved Luescher-Weisz multilevel algorithm tailored for studying excited states of the QCD flux tube, reducing fluctuations more effectively and aligning well with bosonic string model predictions.

Contribution

The paper develops a new version of the Luescher-Weisz algorithm that reduces fluctuations in sources, enhancing the study of excited QCD flux tube states.

Findings

Good agreement with bosonic string model predictions

Enhanced error reduction in excited state measurements

Implementation details of the improved algorithm

Abstract

We present a version of the Luescher-Weisz multilevel algorithm ideally suited for studying excited states of the QCD flux tube. While the original version achieved error reduction only in the temporal direction, the new algorithm reduces fluctuations in the sources as well. We report on the implementation of this algorithm as well as improvement over the older method. We also present first results, where we see a good agreement with theoretical predictions from bosonic string models.