Evidence of nonlocality due to a gradient term in the optical model

TL;DR

This paper shows that adding a velocity-dependent term to the optical model potential introduces nonlocality effects, affecting wave functions inside the nucleus and depending on energy and angular momentum.

Contribution

It demonstrates that a velocity-dependent term in the optical potential can simulate nonlocality, extending understanding of nonlocal effects in nuclear scattering models.

Findings

Nonlocal wave functions differ from local ones due to the velocity-dependent term.

Nonlocality effects depend on energy and angular momentum.

The results align with previous parity-dependent optical potential studies.

Abstract

We demonstrate that the presence of a velocity-dependent term in the phenomenological optical potential simulates a source of nonlocality. This is achieved by showing that, in the interior of the nucleus, the nonlocal wave functions are different from the corresponding local ones obtained in the absence of the velocity-dependent term in accordance with the Perey effect. It is also shown that the enhancement or suppression of the nonlocal wave function is energy as well as angular momentum dependent. The latter is in line with the results of previous works that introduced parity dependent terms in the conventional optical potential.