Treatment of center-of-mass correlations in simulations of nuclear reactions

All nuclear models and approaches are based on the representation of nuclei in their initial state in the form of an ensemble of nucleons with preset spatial coordinates. The nucleon coordinates are usually sampled independently of one another according to a nuclear single-particle density ρA(r). As a result, the sets of nucleon coordinates do not satisfy the obvious requirement Σi=1A ri = 0 that is imposed by center-of-mass correlations. Therefore, it is necessary to preform a dynamic shift of variables that is reduced to replacing ri by ri - Σj=1A rj/A and leads to a distoratoin of the initial ρA(r) distribution. Because the results of simulation are often used to calculate fine characteristics of interactions, efficiencies of experimental facilities, conditions of event selection, etc., these distortions may result in wrong conclusions, and hence, call for the introduction of corrections. A method is proposed in the paper to provide the solution to this problem