Letter Multi-quasiparticle states in 184W via multi-nucleon transfer

A multi-nucleon transfer reaction using an 850 MeV 136Xe beam incident on a 198Pt target was used to populate high-spin states in 184W, 14 nucleons from the target. A 4-quasiparticle isomer with t1/2 = 188 ± 38 ns has been observed for the first time and its de-excitation through collective and intrinsic structures studied. The results are compared with predictions of blocked BCS Nilsson calculations. Obser- vation of this metastable state completes the tungsten 4-quasiparticle isomer systematics from A =1 76 to 186. Mapping out the most yrast 4-quasiparticle isomers in these even-even tungsten isotopes suggests the existence of a highly favoured state in 188W, within reach of current experimental set-ups.