Coulomb distortion and medium corrections in nucleon-removal reactions

TL;DR

This paper investigates how Coulomb distortion and medium modifications of nucleon-nucleon interactions significantly affect the calculation of one-nucleon removal reaction cross sections, especially at lower energies and heavy targets.

Contribution

It provides a comprehensive evaluation of final state interactions and medium effects on nucleon-removal reactions, which are often neglected in previous models.

Findings

Medium effects and Coulomb distortion are significant at energies around 50 MeV/nucleon.

These effects vary with projectile energy, atomic number, and target mass.

Neglecting these effects can lead to substantial inaccuracies in cross section calculations.

Abstract

One-nucleon removal reactions at or above the Fermi energy are important tools to explore the single-particle structure of exotic nuclei. Experimental data must be compared with calculations to extract structure information, evaluate correlation effects in nuclei or determine reaction rates for nuclear astrophysics. However, there is insufficient knowledge to calculate accurately the cross sections for these reactions. We evaluate the contributions of the final state interaction (FSI) and of the medium modifications of the nucleon-nucleon interactions and obtain the shapes and magnitudes of momentum distributions. Such effects have been often neglected in the literature. Calculations for reactions at energies 35 - 1000 MeV/nucleon are reported and compared to published data. For consistency, the state-of-the-art eikonal method for stripping and diffraction dissociation is used. We find that the two effects are important and their relative contributions vary with the energy and with the atomic and mass number of the projectile involved. These two often neglected effects modify considerably the one-nucleon removal cross sections. As expected, the effect are largest at lower energies, around 50 MeV/nucleon and on heavy targets.