  We report a first principle lattice calculation of the pion electric
polarizability $\alpha_\pi$ at the physical pion mass. First, we derive the
master formula, which relates the pion polarizabilities with the position space
hadronic Compton tensor, $\langle \pi | J_\mu(x) J_\nu(0) | \pi \rangle$. The
finite volume error of the master formula is exponentially suppressed by the
spatial extent of the lattice. Then, the hadronic tensor is calculated using
domain wall fermions (DWF) directly at physical pion mass. The gauge ensembles
are generated by the RBC-UKQCD collaborations.
