Investigation of neutron-deficient tungsten isotopes168?174W

Abstract

The decays of168−174W were observed in the reactions of36Ar and40Ar beams with enriched targets of136BaF2 and138BaF2. The measured half-lives are 53(2) s, 76(6) s, 2.42(4) min, 2.38(4) min, 6.6(9) min, 6.3(4) min, and 35.3 (5) min, respectively. Decay schemes were derived from theγ − and X-ray coincidence data. Spin assignments of ground- and excited states are discussed within experimental level systematics and compared with the results of microscopic-macroscopic model calculations. Excitation energies of modeled one-quasiparticle states were found in reasonable agreement with the experimental data. Allowed unhindered beta decay from the 5/2− [523] to the 7/2− [523] configuration was identified in171W and this transition is also proposed for the decays of the even-even isotopes168, 170W.