Generalized polarizability of neutral pions of the process $e^- e^+ \to   \pi^0\pi^0\gamma$ in NJL model
  Differential distributions in the $\pi_0\pi_0\gamma$ system created in the annihilation channel of an electron-positron collision are considered. The energy fractions of the pions (Dalitz-plot) distribution are presented in a general form and in approximation of intermediate vector mesons (excited and ordinary ones).It is pointed out that in relevant experiments the generalized polarizability of the neutral pion can be measured. Numerical illustrations are presented. 
A.I.Ahmadov, E.A.Kuraev, M.K.Volkov
hep-ph