Shell Structure of the Near-Dripline NucleusO23

Abstract

Breakup reactions were used to study the ground-state configuration of the neutron-rich isotope ${}^{23}\mathrm{O}$. The ${}^{22}\mathrm{O}$ fragments produced in one-nucleon removal from ${}^{23}\mathrm{O}$ at $938\mathrm{M}\mathrm{e}\mathrm{V}/\mathrm{\text{nucleon}}$ in a carbon target were detected in coincidence with deexciting $\gamma$ rays. The widths of the longitudinal momentum distributions of the ${}^{22}\mathrm{O}$ fragments and the one-neutron removal cross sections were interpreted in the framework of a simple theoretical model which favors the assignment of $I^{\pi }=1/2^{+}$ to the ${}^{23}\mathrm{O}$ ground state.