A new phenomenon - shifted identical bands and new region of stable octupole deformation

From gamma-gamma-gamma coincidence measurements in the spontaneous fission of Cf-252, level energies were established for spins 14(+) to 20(+) in many neutron-rich nuclei. New isotopes Sm-160 and Gd-162 were identified. The y rast bands of Nd-152,Nd-154,Nd-156, Sm-156,Sm-158,Sm-160, and Gd-160,Gd-162 exhibit remarkably near-identical transition energies and moments of inert ia which are shifted by the same constant amounts for every spin state from 2(+) to 12(+) or 14(+) for nuclei differing by 2n, 4n, 2p, 4p, alpha, alph a+2p, and alpha+2n. These shifted identical bands (SIB) are a new phenomeno n. Analysis of all known even-even proton to neutron-rich nuclei hom Ba (Z = 56) to Os (Z = 76) reveal no SIE for proton-rich nuclei and only a few ad ditional cases of SIE for the most neutron-rich pairs around N = 98-102 sep arated by 2n and 2p. The levels in Mo-107 were extended and levels in Mo-10 9 identified for the first time. Conversion coefficient measurements and level patterns help establish a new region of stable octupole deformation for Mo-107,Mo-109 with N = 85, 67, a ssociated with the nu(d(5/2)-h(11/2)) orbitals. This is the first region ba sed on only one pair of orbitals.