TheN=83 nucleus149Dy from Gamow-Teller decay of its 11/2? and 1/2+ 149Ho parents

Abstract

Abstract. A high-sensitivity 7-spectroscopic study of the 149Ho zchH/2 and z~s~/2 l-decays using mass separated sources has located dominant 0+---,1 + GT decay strength associated with decay of paired h**/2 protons, leading to 3 qp-states in the 149Dy daughter nucleus. In their y-decay low-lying 149Dy levels characteristic of an N= 83 nucleus are excited. They include the v f7~2, vp3/2, vh92 and vp~2 single particle-and the vs -1 and vd -1 / / 1/2 3/2 two-particle one-hole states, as well as the vf7/2 x 3-and vf7/2 x 2 + particle-phonon multiplets. A synopsis is given of these excitations in the N = 83 isotones from raNd to ~53yb. The 149Dy GT decay strength is discussed in terms of the 147Tb82 and 148Dy82 decays. The strength function results are also compared with independent 149Ho 11/2-decay data from the literature based on total y-ray absorption measurements.