2+1 flavor domain wall QCD on a (2 fm)^3 lattice: light meson spectroscopy with Ls = 16

TL;DR

This study uses 2+1 flavor domain wall fermions on a (2 fm)^3 lattice to compute light meson masses and decay constants, achieving results consistent with experimental data and demonstrating the effectiveness of the lattice setup.

Contribution

First lattice calculation of light meson properties using 2+1 flavor domain wall fermions at fixed lattice spacing with detailed extrapolations to physical quark masses.

Findings

Computed f_pi = 127(4) MeV, f_K = 157(5) MeV

Decay constant ratios agree with experimental values

Validated lattice approach for light meson spectroscopy

Abstract

We present results for light meson masses and pseudoscalar decay constants from the first of a series of lattice calculations with 2+1 dynamical flavors of domain wall fermions and the Iwasaki gauge action. The work reported here was done at a fixed lattice spacing of about 0.12 fm on a 16^3\times32 lattice, which amounts to a spatial volume of (2 fm)^3 in physical units. The number of sites in the fifth dimension is 16, which gives m_{res} = 0.00308(4) in these simulations. Three values of input light sea quark masses, m_l^{sea} \approx 0.85 m_s, 0.59 m_s and 0.33 m_s were used to allow for extrapolations to the physical light quark limit, whilst the heavier sea quark mass was fixed to approximately the physical strange quark mass m_s. The exact rational hybrid Monte Carlo algorithm was used to evaluate the fractional powers of the fermion determinants in the ensemble generation. We have found that f_\pi = 127(4) MeV, f_K = 157(5) MeV and f_K/f_\pi = 1.24(2), where the errors are statistical only, which are in good agreement with the experimental values.