Two-point Correlator Fits on HISQ Ensembles

TL;DR

This paper details a comprehensive method for fitting two-point correlators of pseudoscalar mesons using HISQ ensembles, covering various quark masses, lattice spacings, and volumes to extract decay constants and quark mass ratios.

Contribution

It introduces a robust fitting approach with covariance and Gaussian constraints applied to a diverse set of HISQ lattice data for meson physics.

Findings

Preliminary decay constants $f_D$ and $f_{D_s}$ obtained.

Ratios of quark masses derived from fits.

Method applicable across multiple lattice spacings and quark masses.

Abstract

We present our methods to fit the two point correlators for light, strange, and charmed pseudoscalar meson physics with the highly improved staggered quark (HISQ) action. We make use of the least-squares fit including the full covariance matrix of the correlators and including Gaussian constraints on some parameters. We fit the correlators on a variety of the HISQ ensembles. The lattice spacing ranges from 0.15 fm down to 0.06 fm. The light sea quark mass ranges from 0.2 times the strange quark mass down to the physical light quark mass. The HISQ ensembles also include lattices with different volumes and with unphysical values of the strange quark mass. We use the results from this work to obtain our preliminary results of $f_D$, $f_{D_s}$, $f_{D_s}/f_{D}$, and ratios of quark masses presented in another talk [1].