Isomeric Character of the Lowest Observed 4+ State in 44S
Abstract
Previous experiments observed a 4+ state in the N =28 nucleus 44S and suggested that this state may exhibit a hindered E 2 -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 46Ar projectiles and measure its lifetime using the recoil distance method with the GRETINA γ -ray spectrometer. The result, 76 (14 )stat(20 )syst ps , implies a hindered transition of B (E 2 ;4+→21+)=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.
- Publication:
-
Physical Review Letters
- Pub Date:
- February 2017
- DOI:
- 10.1103/PhysRevLett.118.052501
- Bibcode:
- 2017PhRvL.118e2501P