Gamma spectroscopic study of105Ru

Abstract

The 7 radiation following thermal neutron capture in ~~ has been investigated through singles, coincidence, and angular correlation measurements in order to solve existing discrepancies and to complete the knowledge about the transitional odd-N nucleus lo5~.The resulting level and 7-decay scheme is found to be very similar to 441~u61 9that of the odd-Z transitional nucleus 149P_61_mss. Between the 11/2-, 15/2-, and 19/2states which are interpreted as members of the decoupled band, built on the unique parity 11/2-single particle state, low spin states of negative parity are found at surprisingly low excitation energies above the 11/2-state. In the frame of the particleplus-rotor model their positions would require a sharp decrease of the rotational parameter with increasing collective angular momentum of the soft core.