High-$j$ neutron excitations outside $^{136}$Xe

TL;DR

This study investigates high-$j$ neutron excitations outside $^{136}$Xe by measuring spectroscopic factors in $^{137}$Xe, providing new data to refine nuclear shell model predictions near the $N=82$ shell closure.

Contribution

It presents new experimental measurements of neutron excitations in $^{137}$Xe, confirming and reassessing previous states, and offers constraints for theoretical models of similar excitations in $^{133}$Sn.

Findings

Confirmed the second 13/2$^+$ state in $^{137}$Xe.

Reassessed data on 9/2$^-$ states with spectroscopic factors.

Provided constraints for shell model predictions in neighboring isotopes.

Abstract

The $\nu0h_{9/2}$ and $\nu0i_{13/2}$ strength at $^{137}$Xe, a single neutron outside the $N=82$ shell closure, has been determined using the $^{136}$Xe($\alpha$,$^3$He)$^{137}$Xe reaction carried out at 100 MeV. We confirm the recent observation of the second 13/2$^+$ state and reassess previous data on the 9/2$^-$ states, obtaining spectroscopic factors. These new data provide additional constraints on predictions of the same single-neutron excitations at $^{133}$Sn.