Multi-hadron spectroscopy in a large physical volume

TL;DR

This paper demonstrates the effectiveness of the stochastic LapH method for multi-hadron spectroscopy on large-volume lattice QCD ensembles, enabling precise calculations of scattering amplitudes with fewer configurations.

Contribution

The study introduces the stochastic LapH method for all-to-all quark propagator calculations on large physical volumes, improving efficiency in multi-hadron spectroscopy.

Findings

Successful extraction of the elastic isovector p-wave pion-pion scattering amplitude.

Achieved high-precision results with a relatively small number of gauge configurations.

Results suggest feasibility of multi-hadron spectroscopy near physical pion mass with controlled finite-volume effects.

Abstract

We demonstrate the efficacy of the stochastic LapH method to treat all-to-all quark propagation on a $N_f = 2+1$ CLS ensemble with large linear spatial extent $L = 5.5$ fm, allowing us to obtain the benchmark elastic isovector p-wave pion-pion scattering amplitude to good precision already on a relatively small number of gauge configurations. These results hold promise for multi-hadron spectroscopy at close-to-physical pion mass with exponential finite-volume effects under control.