New approach to determine proton-nucleus interactions from experimental bremsstrahlung data

TL;DR

This paper introduces a novel method to extract proton-nucleus interaction details from bremsstrahlung photon data, distinguishing coherent and incoherent emission contributions across different nuclei and energies.

Contribution

The study presents a new model that analyzes bremsstrahlung spectra to determine proton-nucleus potential parameters and emission mechanisms, validated with experimental data.

Findings

Incoherent emission explains the hump-shaped spectra at higher energies.

Coherent emission dominates at low photon energies, producing a logarithmic spectrum.

Predictions for photon angular distributions are provided for future experimental validation.

Abstract

A new approach is presented to determine the proton-nucleus interactions from the analysis of the accompanying photon bremsstrahlung. We study the scattering of $p + ^{208}{\rm Pb}$ at the proton incident energies of 140 and 145~MeV, and the scattering of $p + ^{12}{\rm C}$, $p + ^{58}{\rm Ni}$, $p + ^{107}{\rm Ag}$ and $p + ^{197}{\rm Au}$ at the proton incident energy of 190~MeV. The model determines contributions of the coherent emission (formed by an interaction between the scattering proton and nucleus as a whole without the internal many-nucleon structure), incoherent emission (formed by interactions between the scattering proton and nucleus with the internal many-nucleon structure), and transition between them in dependence on the photon energy. The radius-parameter of the proton-nucleus potential for these reactions is extracted from the experimental bremsstrahlung data analysis. We explain the hump-shaped plateau in the intermediate- and high-energy regions of the spectra by the essential presence of the incoherent emission, while at low energies the coherent emission predominates which produces the logarithmic shape spectrum. We provide our predictions (in absolute scale) for the angular distribution of the bremsstrahlung photons in order to test our model, results and analysis in further experiments.