The investigation of nonlocality effects for the nucleon-nucleus optical potential

The nucleon-nucleus optical potential is calculated within the framework of the Watson multiple-scattering theory in the first order for the collision number. Nonlocality effects under consideration are due to the off-shell and angular dependence of the nucleon-nucleon t-matrix. It is shown that the account of nonlocality of the optical potential increases the probability for nucleon to be in the range with sizes of the order of the NN-interaction radius. The relation of this phenomenon to the Perey effect is discussed. Calculations of the total nucleon-nucleus scattering cross sections at intermediate energies are carried out, and results are compared with the experimental data and results obtained by other authors. (author)