Electric Polarizability of Mesons in Semirelativistic Quark Models
  The electric polarizability of mesons, in particular, that of the charged pion, is studied in the framework of a semirelativistic description of hadrons as bound states of valence quarks in terms of a Hamiltonian composed of the relativistic kinetic energy as well as a phenomenological potential describing the strong interactions between the quarks. The quark-core contribution to the electric polarizability obtainable in quark models of this kind turns out to be in the semirelativistic approaches even smaller than in the nonrelativistic limit. 
Wolfgang Lucha and F.F.Schoberl