ON THE FORWARD ANGLE DISPERSION SUM-RULES FOR THE PION POLARIZABILITIES

We discuss the pion polarizabilities alpha(pi), beta(pi) using a vecto r dominance model. We show that the vector-meson contribution accounts for almost 80% of the pi0 forward angle dispersion sum rule. By inclu ding the spin 2 resonance contribution and the recently reported calcu lation of the loop diagrams of order O(p6), we find a very good agreem ent with the values of the sum rule obtained from the optical theorem, for both the pi+/- and pi0.