We present an update on our results of nucleon form factors measured on a large-volume lattice (8:1fm)4 at almost the physical point in 2+1 flavor QCD. The configurations are generated with the stout-smeared O(a) improved Wilson quark action and Iwasaki gauge action at β = 1:82, which corresponds to the lattice spacing of 0.085 fm. The pion mass at the simulation point is about 145 MeV. We determine the isovector electric radius and magnetic moment from nucleon electric (GE) and magnetic (GM) form factors. We also report on preliminary results of the axial-vector (FA), induced pseudo-scalar (FP) and pseudo-scalar (GP) form factors in order to verify the axial Ward-Takahashi identity in terms of the nucleon matrix elements, which may be called as the generalized Goldberger-Treiman relation.
Nucleon form factors near the physical point in 2+1 flavor QCD