Proton elastic scattering from tin isotopes at 295 MeV and systematic change of neutron density distributions

TL;DR

This study measures proton elastic scattering from tin isotopes at 295 MeV to systematically analyze changes in neutron density distributions and neutron skin thickness across isotopes.

Contribution

It introduces a method using tuned relativistic interactions to extract neutron density distributions from scattering data, revealing systematic neutron skin growth.

Findings

Neutron skin thickness increases with tin isotope mass number.

The relativistic Love-Franey interaction effectively models proton scattering.

Systematic neutron density changes are observed across isotopes.

Abstract

Cross sections and analyzing powers for proton elastic scattering from $^{116,118,120,122,124}$Sn at 295 MeV have been measured for a momentum transfer of up to about 3.5 fm$^{-1}$ to deduce systematic changes of the neutron density distribution. We tuned the relativistic Love-Franey interaction to explain the proton elastic scattering of a nucleus whose density distribution is well known. Then, we applied this interaction to deduce the neutron density distributions of tin isotopes. The result of our analysis shows the clear systematic behavior of a gradual increase in the neutron skin thickness of tin isotopes with mass number.