Bridging reaction theory and nuclear structure in $\pi^\pm$-${}^{48}$Ca scattering

TL;DR

This paper enhances pion-nucleus scattering models by incorporating second-order rescattering effects and detailed nuclear structure, improving the accuracy of differential cross section predictions for $ ext{pi}^ ext{±}$-${}^{48} ext{Ca}$ scattering.

Contribution

It introduces a comprehensive scattering potential including charge-exchange and spin-flip effects, and utilizes advanced nuclear density calculations from coupled-cluster and Hartree-Fock methods.

Findings

Second-order corrections significantly improve cross section predictions.

Nuclear structure details have mild sensitivity on scattering results.

Uncertainty estimates are provided using chiral effective field theory Hamiltonians.

Abstract

We extend the pion-nucleus multiple-scattering framework to include detailed second-order rescattering dynamics for nuclei with non-zero isospin. To account for intermediate charge-exchange and nucleon spin-flip effects, we develop a scattering potential that depends on the one- and two-body densities of the target nucleus. We compute one-body densities from coupled-cluster theory and two-body densities within the Hartree-Fock approximation. To estimate theoretical uncertainties, we employ modern nuclear Hamiltonians derived from chiral effective field theory. While the sensitivity to nuclear structure details is mild, second-order corrections are found to be sizeable and essential for accurately reproducing differential cross sections measured in $\pi^\pm$-${}^{48}$Ca elastic scattering within the $\Delta(1232)$-resonance region