Negative pion photoproduction on bound nucleons

The kinematic aspect of the effects of escape from the mass surface in the reaction of photoproduction of negative pions on neutrons bound in the 12C nucleus is studied. In the framework of pulse approximation with distorted waves and nucleus shell model the differential cross section of the 12C(γ, π-p)11C reaction measured in the range of the Δ(1232) resonance photoexcitation is analysed. The energy dependence of the cross section dσ/dΩ of the n(γ, π-)p reaction is found. The absolute value of the cross section dσ/dΩ of the n(γ, π-)p reaction on 12C nucleus neutrons in the range of the Δ(1232) resonance excitation coincides with the cross section extracted from the 2H(γ, π-p)p reaction experimental data. The energy dependence maximum state of experimental cross section is best described in kinematic dσ/dΩ determination of pion or proton by means of momentum of finite state particles of the 12C(γ, π-p)11C reaction or using any other sufficient set of kinematic three-particle reaction variables when taking into account that nuclear neutrons are located beyond mass surface (neutron mass is accepted to be equal [(msub(A)-Esub(r))sup(2)-Psub(r)sup(2)]sup(1/2). The assumption on considerable Δ(1232) parameter distortion in carbon photoproduction has not been confirmed