LOW-LYING STATES IN HO-153 AND TM-157 FROM ELECTRON-CAPTURE AND BETA(-153 AND YB-157() DECAY OF ER)

A detailed discussion and supplemental experimental information on the electron capture and beta(+) decay schemes of Er-153 and Yb-157 propo sed in our previous publications are included. The three-quasiparticle state and single-proton states assigned to Ho-153 have been reproduce d by a shell model calculation. The extracted quenching factor for the three-quasiparticle state was determined to be 10. The existence of t he two bands in Tm-157 has been explained by a triaxial deformation of the ground state of this nucleus. The experimental evidence from syst ematic behavior of the compiled low-energy levels indicates that the g round-state shapes change from spherical to deformed between neutron n umbers N=86 and 88 in both the odd Ho and odd Tm isotopic chains.