Utility of antiproton-nucleus scattering for probing nuclear surface density distributions

TL;DR

This paper explores how antiproton-nucleus scattering, due to its large cross sections, can serve as a sensitive probe of nuclear surface density distributions, especially in the tail region, using Glauber model calculations.

Contribution

It demonstrates the potential of antiproton scattering to probe nuclear surface densities more effectively than protons, highlighting the absorption beyond the nuclear radius.

Findings

Antiproton-nucleus reactions are well described by the Glauber model.

Complete absorption occurs beyond the nuclear radius due to large $ar{p}N$ cross sections.

Antiproton scattering shows enhanced sensitivity to nuclear surface density distributions.

Abstract

Antiproton-nucleon ($\bar{p}N$) total cross sections are typically 3-4 times larger than the $NN$ ones at incident energies from a few hundreds to thousands MeV. We investigate antiproton-nucleus scattering as it could work as a probe of the nuclear structure giving the sensitivity differently from a proton probe. High-energy antiproton-nucleus reactions are reasonably described by the Glauber model with a minimal profile function that reproduces the $\bar{p}N$ and $\bar{p}$-$^{12}$C cross section data. In contrast to the proton-nucleus scattering, we find that the complete absorption occurs even beyond the nuclear radius due to the large $\bar{p}N$ elementary cross sections, which shows stronger sensitivity to the nuclear density distribution in the tail region. This sensitivity is quantified in the total reaction cross sections with various density profiles for future measurement including neutron-rich unstable nuclei.