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

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 163×32 lattice, which amounts to a spatial volume of (2fm)3 in physical units. The number of sites in the fifth dimension is 16, which gives mres=0.00308(4) in these simulations. Three values of input light sea quark masses, mlsea 0.85ms, 0.59ms and 0.33ms were used to allow for extrapolations to the physical light quark limit, while the heavier sea quark mass was fixed to approximately the physical strange quark mass ms. 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 fπ=127(4)MeV, fK=157(5)MeV and fK/fπ=1.24(2), where the errors are statistical only, which are in good agreement with the experimental values.