Isomeric character of the 4$^{+}_{1}$ state in $^{44}$S: Mechanisms of breaking of the N$=$28 shell

The N$=$28 nucleus $^{44}$S exhibits a rich structure of excitations which illustrates different mechanisms of breaking the N$=$28 shell. A Coulomb excitation measurement [1] and an implantation-decay experiment [2] established the coexistence of 2p2h-deformed and 0p0h-spherical configurations. A two-proton knockout reaction [3] indicated a 4$^{+}$ state which shell model calculations suggest is likely isomeric, prolate-deformed and formed from a 1p1h configuration. A recent two-proton knockout experiment measured the lifetime of this 4$^{+}$ state using the recoil distance method and the GRETINA array. Results for the lifetime of the 4$^{+}$ state will be presented and its implication for the mechanisms of breaking the N$=$28 shell will be discussed.\\[4pt] [1] T. Glasmacher \textit{et al.}, Phys.Lett. \textbf{B 395} (1997), 163 \newline [2] C. Force \textit{et al.}, Phys.Rev.Lett. \textbf{105}, 102501 (2010) \newline [3] D. Santiago-Gonzalez \textit{et al.} Phys.Rev. \textbf{C 83}, 061305 R (2012)