ar X iv : h ep - p h / 03 06 25 6 v 2 2 6 M ar 2 00 4 Features of high energy pp and pA elastic scattering at small t

Features of high energy pp and pA elastic scattering at small t Abstract A method for the determination of the real part of the elastic scattering amplitude is examined for high energy proton-proton and proton-nuclei elastic scattering at small momentum transfer. This method allows us to decrease the number of model assumptions, to obtain the real parts of the spin-non-flip and spin-flip amplitudes in a narrow region of momentum transfer. A large number of experimental and theoretical studies of the high energy elastic proton-proton and proton-antiproton scattering at small angles gives a rich information about this processes and allows to narrow the circle of examined models and to solve a number of difficult problems. Especially this concerns the energy dependence of some of characteristics of these reactions and the contribution of the odderon. Some of these questions are connected with the s and t dependence of the spin-non-flip phase of hadron-hadron scattering. The most of the models define the real part of the scattering amplitude phenomenologically. Some models use local dispersion relations and the hypothesis of the geometrical