Chiral Vibrations and Collective Bands in 104 Mo

Furman Hall 111

High spin states of the neutron-rich 104Mo nucleus which is known to be triaxial have been reinvestigated by analyzing the γ-rays in the spontaneous fission of 252Cf with Gammasphere. Both γ-γ-γ and γ-γ-γ-γ coincidence data were analyzed. A new ∆I=1 band has been discovered. The new band is proposed to have a tentative 5− band head and form a class of chiral doublets with another 4− band previously found by our group [1]. Angular correlation measurements have been performed to determine spin and parity of the 4− chiral band head. The energies of the two sets of chiral bands are very similar to the chiral bands observed in 106Mo [2], e.g. the two 5− levels in 104Mo are at 2211.9 and 2276.8 keV with ∆E=65 keV and in 106Mo, 1952.4 and 2090.6 keV with ∆E=138 keV [2]. Now at every spin 5−, 6−, 7−, 8−, the separation energies of the same spin states are about a factor of two smaller than in 106Mo. This indicates even better agreement with expectations for two sets of chiral bands.