Meson correlators in the epsilon-regime of two-flavor lattice QCD

Abstract

We calculate the meson correlators in the $\epsilon$-regime of two-flavor QCD. On a $16^3\times 32$ lattice with $a\sim 0.11$ fm, the lattice simulations are performed with the dynamical overlap fermions. We reduce the sea quark mass down to $\sim$ 3 MeV and the valence quark masses are taken in the range 1-4 MeV. The meson correlators in various channels are compared with the predictions of (partially quenched) chiral perturbation theory (ChPT). Including the NLO order of the $\epsilon$-expansion, we extract the leading-order low energy constants of ChPT, the pion decay constant $F$ and the chiral condensate $\Sigma$, as $F=87.3(5.5)$ MeV and ${\Sigma }^{\overline{\mathrm{MS}}}=[237.8(4.0)MeV{]}^3$.

7pages, 4figures. Presented at Lattice 2007, Regensburg, Germany, 30 Jul - 4 Aug 2007, minor corrections in figures