Progress on the spectroscopy of lattice gauge theories using spectral densities

TL;DR

This paper advances the non-perturbative analysis of strongly coupled lattice gauge theories by developing spectral density reconstruction techniques, applying them to Sp(4) gauge theory, and providing publicly available analysis tools.

Contribution

It introduces a systematic spectral density reconstruction method for lattice gauge theories and applies it to analyze meson spectra in Sp(4) gauge theory, with publicly available code.

Findings

Successful reconstruction of spectral densities for lattice data

Measurement of meson masses across multiple channels

Identification of excited states in the meson spectrum

Abstract

Spectral densities encode non-perturbative information crucial in computing physical observables in strongly coupled field theories. Using lattice gauge theory data, we perform a systematic study to demonstrate the potential of recent technological advances in the reconstruction of spectral densities. We develop, maintain and make publicly available dedicated analysis code that can be used for broad classes of lattice theories. As a test case, we analyse the Sp(4) gauge theory coupled to an admixture of fermions transforming in the fundamental and two-index antisymmetric representations. We measure the masses of mesons in energy-smeared spectral densities, after optimising the smearing parameters for available lattice ensembles. We present a summary of the mesons mass spectrum in all the twelve (flavored) channels available, including also several excited states.