Pion form factor from 2+1 dynamical flavor lattice QCD using the O(a) improved Wilson-clover quark formalism

We present a status report of our calculation of the electromagnetic form factor of the pion on the PACS-CS gauge field configurations generated using Iwasaki gauge action and Wilson-clover quark action for 2 + 1 flavors of light dynamical quarks. The technique of twiseted boundary conditon is employed to explore the form factor for small momentum transfer. The $q^2$ behavior of the form factor and its light quark mass dependence is examined.