Spectroscopy of $^{33}$Mg with knockout reactions

TL;DR

This study investigates the structure of $^{33}$Mg using knockout reactions, revealing its negative parity ground state and providing insights into its complex configuration mixing within the island of inversion.

Contribution

It combines experimental knockout reactions with theoretical shell model calculations to resolve the parity controversy and analyze the structure of $^{33}$Mg.

Findings

Confirmed negative parity of $^{33}$Mg ground state

Measured partial cross sections consistent with shell model predictions

Provided detailed insight into the configuration mixing in $^{33}$Mg

Abstract

The structure of $^{33}$Mg was investigated by means of two knockout reactions, one-neutron removal from $^{34}$Mg and one-proton removal from $^{34}$Al. Using comparative analysis of the population of observed excited states in the residual $^{33}$Mg, the nature of these states can be deciphered. In addition, the long-standing controversy about the parity of the $^{33}$Mg ground state is resolved using momentum distribution analysis, showing a clear signature for negative parity. Partial cross section measurements are compared with the results of eikonal reaction theory combined with large-scale shell model calculations of this complex nucleus located in the island of inversion, where configuration mixing plays a major role.