Chiral extrapolations in 2+1 flavor domain wall fermion simulations

Simulations with 2+1 flavors of domain wall fermions provide us with the opportunity to compare the lattice data directly to the predictions of continuum chiral perturbation theory, up to corrections from the residual chiral symmetry breaking, $m_{res}$, and $O(a)$ lattice artefacts, which are relatively small for domain wall fermions. We present preliminary results for the pseudoscalar meson masses and decay constants from partially quenched simulations and examine the next-to-leading order chiral extrapolations at small quark masses. The simulations were carried out on two lattice volumes : $16^3\times 32$ and $24^3\times 64$, with the lattice spacing fixed at about 0.1 fm. The subtleties of the chiral fits are discussed. We also explore the roles of $m_{res}$ and $O(a)$ terms in the NLO chiral expansions and their effects on the chiral extrapolations for the pseudoscalar masses and decay constants.