Polarizabilities reveal valuable information on the internal structure of hadrons in terms of charge and current distributions. For neutral hadrons, the standard approach is the background field method. But for a charged hadron, its acceleration under the applied field complicates the isolation of the polarization energy. In this work, we explore an alternative method based on four-point functions in lattice QCD. The approach offers a transparent picture on how polarizabilities arise from quark and gluon interactions. We carry out a proof-of-concept simulation on the electric polarizability of a charged pion,
using quenched Wilson action on a $24^3\times 48$ lattice at $\beta=6.0$ with pion mass from 1100 to 370 MeV.
We report results on charge radius and electric polarizability.
Our results from connected diagrams suggest that charged pion $\alpha_E$ is due to a large cancellation between elastic and inelastic contributions, leaving a small and positive value that has a relatively mild pion mass dependence.