Isomeric Character of the Lowest Observed 4^{+} State in ^{44}S.

Previous experiments observed a 4(+) state in the N = 28 nucleus S-44 and suggested that this state may exhibit a hindered E2-decay rate, inconsistent with being a member of the collective ground state band. We populate this state via two-proton knockout from a beam of exotic Ar-46 projectiles and measure its lifetime using the recoil distance method with the GRETINA gamma-ray spectrometer. The result, 76(14)(stat)(20)(syst) ps, implies a hindered transition of B(E2; 4(+) -> 2(1)(+)) = 0.61(19) single-particle or Weisskopf units strength and supports the interpretation of the 4(+) state as a K = 4 isomer, the first example of a high-K isomer in a nucleus of such low mass.