In-beam spectroscopic studies of ${}^{44}$S nucleus

The structure of the ${}^{44}$S nucleus has been studied at GANIL through the one proton knock-out reaction from a ${}^{45}$Cl secondary beam at 42 A$\cdot$MeV. The $\gamma$ rays following the de-excitation of ${}^{44}$S were detected in flight using the 70 BaF${}_2$ detectors of the Ch^{a}teau de Cristal array. An exhaustive $\gamma \gamma$-coincidence analysis allowed an unambiguous construction of the level scheme up to an excitation energy of 3301 keV. The existence of the spherical 2${}_2^{+}$ state is confirmed and three new $\gamma$-ray transitions connecting the prolate deformed 2${}_1^{+}$ level were observed. Comparison of the experimental results to shell model calculations further supports a prolate and spherical shape coexistence with a large mixing of states built on the ground state band in ${}^{44}$S.