Résumé : The tremendous change in the pattern of the Wilczynski curves for deep inelastic reactions with the product Z1Z2 is interpreted within a model including both dissipation and statistical fluctuations. The competition between Coulomb and nuclear forces seems to account for this effect. NUCLEAR REACTIONS Calculation of double differential cross sections d2σd θdE for deep inelastic reactions. © 1978 The American Physical Society.