First Experimental Test of the Ratio Method

TL;DR

This paper reports the first experimental validation of the ratio method, a new approach to extract structure information on halo nuclei by using the ratio of scattering and breakup cross sections, demonstrating its robustness across different targets.

Contribution

The paper provides the first experimental test of the ratio method for halo nuclei, confirming its effectiveness and independence from reaction dynamics.

Findings

The ratio of cross sections is smooth and target-independent.

The method is validated for both light and heavy targets.

Experimental data supports the theoretical predictions.

Abstract

The ratio is a new reaction observable suggested to extract accurately structure information on halo nuclei. It corresponds to the ratio of differential cross sections for scattering and breakup, which is predicted to remove the uncertainty related to the reaction dynamics. We present here the first experimental test of the method for the 11Be + 12C collision at ELab = 20A MeV performed at Texas A&M University. Differential cross sections for scattering and inclusive one-neutron breakup have been measured with the new detector array BlueSTEAl. The ratio of cross sections is very smooth and independent of the projectile-target interaction, which demonstrates the validity of the ratio method. We extend our analysis to existing 11Be + 208Pb data, confirming that the method works well on any target.