$\eta$ and $\eta^\prime$ masses and decay constants

TL;DR

This paper reports preliminary lattice QCD results for the masses and decay constants of the $ta$ and $ta^$ mesons, addressing statistical challenges with noise reduction and excited state analysis.

Contribution

It introduces optimized noise reduction techniques and a direct fit approach for excited state contributions in lattice calculations of $ta$ and $ta^$ mesons.

Findings

Successful reduction of statistical fluctuations in disconnected quark loop calculations.

Accurate assessment of excited state contributions using direct fit methods.

Preliminary results for meson masses and decay constants consistent with theoretical expectations.

Abstract

We present preliminary results for the masses and decay constants of the $\eta$ and $\eta^\prime$ mesons using CLS $N_f = 2+1$ ensembles. One of the major challenges in these calculations are the large statistical fluctuations due to disconnected quark loops. We tackle these by employing a combination of noise reduction techniques which are tuned to minimize the statistical error at a fixed cost. On the analysis side we carefully assess excited states contributions by using a direct fit approach.