Asymmetry of the parallel momentum distribution of (p,pN) reaction residues

TL;DR

This study investigates the asymmetric shape of the parallel momentum distribution of residual nuclei in specific (p,pN) reactions at high energies, revealing effects due to phase volume and nucleon potential interactions.

Contribution

It introduces a detailed analysis of the asymmetry in PMD shapes using the distorted wave impulse approximation, highlighting the physical origins of the observed asymmetry.

Findings

Asymmetry characterized by steep fall-off and long tail in PMD.

Phase volume effect causes high momentum fall-off.

Nucleon potential shifts contribute to low momentum tail.

Abstract

The parallel momentum distribution (PMD) of the residual nuclei of the 14O(p,pn)13O and 14O(p,2p)13N reactions at 100 and 200 MeV/nucleon in inverse kinematics is investigated with the framework of the distorted wave impulse approximation. The PMD shows an asymmetric shape characterized by a steep fall-off on the high momentum side and a long-ranged tail on the low momentum side. The former is found to be due to the phase volume effect reflecting the energy and momentum conservation, and the latter is to the momentum shift of the outgoing two nucleons inside an attractive potential caused by the residual nucleus. Dependence of these effects on the nucleon separation energy of the projectile and the incident energy is also discussed.