Rotational and neutron-hole states in ${}^{43}\mathrm{S}$ via the neutron knockout and fragmentation reactions

The recent assertion that shape coexistence occurs in the neutron-rich isotope ${}^{43}\mathrm{S}$ implies that a state observed at 940 keV in a previous study is a rotational excitation of the deformed ground state. Here we use results from two intermediate-energy reactions to demonstrate that this state—assigned an energy of 971 keV in the present work—is indeed a rotational state. This result strengthens the case for shape coexistence in ${}^{43}\mathrm{S}$.

Figure 1

Gamma-ray spectra measured in coincidence with recoiling ${}^{43}\mathrm{S}$ particles produced via one-neutron knockout (a) and fragmentation (b). The solid curves are GEANT4 fits described in the text.

Figure 2

The level scheme of ${}^{43}\mathrm{S}$ deduced in the present work.

Figure 3

Comparison of the experimental level scheme of ${}^{43}\mathrm{S}$ with the results of the shell-model calculation described in the text.