Systematics of isomeric configurations in N=77 odd-Z isotones near the proton drip line
The systematics of the πh11/2 νh11/2 and πh11/2 νs1/2 isomeric configurations was studied for the odd-Z N=77 isotones near the proton drip line. The isomeric decays in Eu140, Tb142, Ho144, and Tm146 were measured by means of x-ray, γ-ray, and charged particle spectroscopy at the Recoil Mass Spectrometer at the Holifield Radioactive Ion Beam Facility (ORNL). The spin and parity of Iπ=8+ and 5- were deduced for the isomers in Eu140 and Tb142. New decay schemes were established, and the half-lives of the 8+ isomers were measured to be 302(4) ns for Eu140m2 and 25(1) μs for Tb142m2. No evidence for the expected 1+ ground-state was found in the Ho144 decay data. The proton-emission from Tm146 was restudied. Five proton transitions were assigned to two proton-emitting states. The half-lives of 198(3) ms and 68(3) ms and the spin and parity values of Iπ=10+ and 5- were established for Tm146m and Tm146gs, respectively. For the first time for an odd-odd nucleus, the interpretation of the observed decay properties and structure of the proton-emitting states was made by accounting for deformation and proton and neutron coupling to the core excitations. A complex wave-function structure was obtained, with dominating components of πh11/2 νh11/2 for the 10+ isomer and πh11/2 νs1/2 for the 5- ground state. © 2006 The American Physical Society.
Publication Source (Journal or Book title)
Physical Review C - Nuclear Physics
Tantawy, M., Bingham, C., Rykaczewski, K., Batchelder, J., Królas, W., Danchev, M., Fong, D., Ginter, T., Gross, C., Grzywacz, R., Hagino, K., Hamilton, J., Hartley, D., Karny, M., Li, K., Mazzocchi, C., Piechaczek, A., Ramayya, A., Rykaczewski, K., Shapira, D., Stolz, A., Winger, J., Yu, C., & Zganjar, E. (2006). Systematics of isomeric configurations in N=77 odd-Z isotones near the proton drip line. Physical Review C - Nuclear Physics, 73 (2) https://doi.org/10.1103/PhysRevC.73.024316