A Predictive Theory for Elastic Scattering and Recoil of Protons from $^4$He

TL;DR

This paper presents a theoretical calculation of low-energy proton scattering and recoil from helium-4 nuclei using advanced nuclear forces, aiding material analysis and resolving experimental data inconsistencies.

Contribution

It introduces direct Schrödinger equation solutions with chiral effective field theory forces for accurate cross section predictions.

Findings

Calculated cross sections match experimental data.

Results help resolve data inconsistencies.

Predictions assist in materials analysis applications.

Abstract

Low-energy cross sections for elastic scattering and recoil of protons from $^4$He nuclei (also known as $\alpha$ particles) are calculated directly by solving the Schr\"odinger equation for five nucleons interacting through accurate two- and three-nucleon forces derived within the framework of chiral effective field theory. Precise knowledge of these processes at various proton backscattering/recoil angles and energies is needed for the ion-beam analysis of numerous materials, from the surface layers of solids, to thin films, to fusion-reactor materials. Indeed, the same elastic scattering process, in two different kinematic configurations, can be used to probe concentrations and depth profiles of either hydrogen or helium. We compare our results to available experimental data and show that direct calculations with modern nuclear potentials can help to resolve remaining inconsistencies among different data sets and can be used to predict these cross sections when measurements are not available.