Experimental estimation of the sum of pion electrical and magnetic polarizabilities

The pion radiative scattering πZ→πZγ at 40 GeV was investigated. Coulomb scattering-i.e. pion Compton-effect-dominates for small fourmomentum transfers in this reaction. In our previous paper we found the pion polarizability to beβ π =(−6.8±1.4)·10−43, cm3, where we assume following the theory that the sum of electrical and magnetic polarizabilities (α π +β π )≃0. More complete analysis of our data is done in order to test this assumption. The result for (α π +β π ) is in agreement with theoretical predictions.