Many-body effects in (p,pN) reactions within a unified approach

TL;DR

This paper develops a unified theoretical approach combining Quantum Monte Carlo wave functions with few-body reaction formalism to study knockout reactions, providing new insights into nuclear correlations and structure.

Contribution

It introduces a novel combined framework for analyzing (p,pN) reactions using ab initio wave functions, achieving results consistent with experimental data for light nuclei.

Findings

Ratios between ab initio and mean-field cross sections depend on nucleon separation energy.

Correlations are stronger for more deficient nucleons.

Protons in $^{12}$C show higher correlation than neutrons.

Abstract

We study knockout reactions with proton probes within a theoretical framework where {\it ab initio} Quantum Monte Carlo wave functions are combined with the Faddeev/Alt-Grassberger-Sandhas few-body reaction formalism. New Quantum Monte Carlo wave functions are used to describe $^{12}$C, yielding, for the first time, results consistent with the experimental point rms radii, electron scattering data and (p,2p) total cross sections data. Our results for $\mathrm{A}\leq 12$ and $(N-Z) \leq 3$ nuclei show that the theoretical ratios between the (i) {\it ab initio} and Mean Field Approximation theoretical cross sections, $\mathcal{R}_\sigma$, (ii) corresponding ratios between the spectroscopic factors, $\mathcal{R}_\Sigma$, summed over states below particle emission, depend moderately on the nucleon separation energy S$_{\rm N}$. These ratios are determined by a delicate interplay between the radii of the parent and the residual nuclei and the nucleon separation energy, and were found to be always smaller for the knockout of the more correlated deficient species nucleon. In the case of the symmetric $^{12}$C nucleus, the theoretical ratios still appear to indicate that protons are more correlated than neutrons.