Excitation of heavy hydrogen-like ions by light atoms in relativistic collisions with large momentum transfers

TL;DR

This paper develops a theoretical model for the excitation of heavy hydrogen-like ions by light atoms during relativistic collisions with large momentum transfers, emphasizing the roles of atomic electrons and nucleus.

Contribution

It introduces a new theory accounting for large momentum transfer collisions, highlighting the quasi-free behavior of atomic particles and the influence of the ion's nuclear field.

Findings

Atomic electrons and nucleus behave as quasi-free particles during collisions.

The atomic nucleus's field can be neglected due to its large mass.

The atomic electrons' excitation contribution is significantly affected by the ion's nuclear field.

Abstract

We present a theory for excitation of heavy hydrogen-like projectile-ions by light target-atoms in collisions where the momentum transfers to the atom are very large on the atomic scale. It is shown that in this process the electrons and the nucleus of the atom behave as (quasi-) free particles with respect to each other and that their motion is governed by the field of the nucleus of the ion. The effect of this field on the atomic particles can be crucial for the contribution to the excitation of the ion caused by the electrons of the atom. Due to comparatively very large nuclear mass, however, this field can be neglected in the calculation of the contribution to the excitation due to the nucleus of the atom.