Hadron spectrum, quark masses, and decay constants from light overlap fermions on large lattices

Abstract

We present results from a simulation of quenched overlap fermions with L\"uscher-Weisz gauge field action on lattices up to ${24}^{3}48$ and for pion masses down to $\ensuremath{\approx}250\text{ }\text{ }\mathrm{MeV}$. Among the quantities we study are the pion, rho, and nucleon masses; the light and strange quark masses; and the pion decay constant. The renormalization of the scalar and axial vector currents is done nonperturbatively in the RI-MOM scheme. The simulations are performed at two different lattice spacings, $a\ensuremath{\approx}0.1\text{ }\text{ }\mathrm{fm}$ and $\ensuremath{\approx}0.15\text{ }\text{ }\mathrm{fm}$, and on two different physical volumes, to test the scaling properties of our action and to study finite volume effects. We compare our results with the predictions of chiral perturbation theory and compute several of its low-energy constants. The pion mass is computed in sectors of fixed topology as well.