Topological susceptibility in two flavors lattice QCD with the optimal domain-wall fermion

Abstract

We determine the topological susceptibility of the gauge configurations generated by lattice simulations using two flavors of optimal domain-wall fermion on the 163×32 lattice with length 16 in the fifth dimension, at the lattice spacing a≃0.1 fm. Using the adaptive thick-restart Lanczos algorithm, we project the low-lying eigenmodes of the overlap Dirac operator, and obtain the topological charge of each configuration, for eight ensembles with pion masses in the range 220–550 MeV. From the topological charge, we compute the topological susceptibility and the second normalized cumulant. Our result of the topological susceptibility agrees with the sea-quark mass dependence predicted by the chiral perturbation theory and provides a determination of the chiral condensate, ΣMS¯(2 GeV)=[259(6)(7) MeV]3, and the pion decay constant Fπ=92(12)(2) MeV.