SPLITTING OF THE NEUTRON AND PROTON ELECTRIC POLARIZABILITIES IN A HEDGEHOG MODEL

Proton and neutron proper (static) electric polarizabilies, alpha(n) and alpha(p), are calculated in a chiral soliton model with quarks and mesons. Semiclassical methods (1/N(c) expansion, cranking, linear response theory) are used. We find alpha(n)>alpha(p), and the splitting effect is of the order of 1/N(c). Its magnitude, 5.4 X 10(-4) fm, agrees with recent experimental data. The average nucleon polarizability is of the order of N(c). The numerical value of this quantity obtained from our semiclassical method is roughly a factor of three larger-than the experimental value. This is because the contribution of pion-DELTA intermediate states is artificially enhanced in hedgehog models.