Excited isovector mesons using the stochastic LapH method

TL;DR

This study investigates the spectrum of excited isovector mesons using advanced lattice QCD techniques, including large correlation matrices and stochastic methods, to improve the understanding of meson properties at near-physical pion masses.

Contribution

The paper introduces the use of the stochastic LapH method with large correlation matrices to analyze excited isovector mesons on anisotropic lattices, enhancing computational efficiency and spectral resolution.

Findings

Successful extraction of excited isovector meson spectra.

Implementation of stochastic LapH method for efficient Wick contractions.

Analysis includes a variety of meson operators and momenta.

Abstract

The spectrum of excited isovector mesons is studied using a 32^3 x 256 anisotropic lattice with u,d quark masses set to give a pion mass near 240 MeV. Results in the bosonic isovector nonstrange symmetry channels of zero total momentum are presented using correlation matrices of unprecedented size. In addition to spatially-extended single-meson operators, large numbers of two-meson operators are used, involving a wide variety of light isovector, isoscalar, and strange meson operators of varying relative momenta. All needed Wick contractions are efficiently evaluated using a stochastic method of treating the low-lying modes of quark propagation that exploits Laplacian Heaviside quark-field smearing. Level identification is discussed.