First Extraction of the Matter Radius of $^{132}$Sn via Proton Elastic Scattering at 200 MeV/Nucleon

TL;DR

This study measured the matter radius of $^{132}$Sn using proton elastic scattering at high energies, providing new experimental data that challenges existing theoretical models when combined with charge radius measurements.

Contribution

First experimental extraction of the matter radius of $^{132}$Sn via proton elastic scattering at 200 MeV/nucleon.

Findings

Measured the differential cross sections over a wide momentum transfer range.

Extracted the matter radius of $^{132}$Sn as approximately 4.758 fm.

Found discrepancies between experimental data and theoretical calculations when combined with charge radius.

Abstract

The angular distribution of the differential cross sections for proton elastic scattering from $^{132}$Sn at 196-210 MeV/nucleon was successfully measured over a momentum transfer range of 0.80 to 2.1 fm$^{-1}$. Using a relativistic impulse approximation, the root-mean-square matter radius of $^{132}$Sn was extracted to be $4.758^{+0.023}_{-0.024}$ fm, which was compared with the state-of-the-art ab initio calculations. Combined with the charge radius measured at ISOLDE, there are no theoretical calculations consistent with both matter and charge radii within the experimental errors.