Isomeric low-lying states were identified and investigated in the 75 Cu nucleus. Two states at 61.8(5)-and 128.3(7)-keV excitation energies with half-lives of 370(40)-and 170(15)-ns were assigned as 75m1 Cu and 75m2 Cu, respectively. The measured half-lives combined with the recent spin assignment of the ground state allow one to deduce tentatively spin and parity of the two isomers and the dominant multipolarities of the isomeric transitions with respect to the systematics of the Cu isotopes. Shell-model calculations using an up-to-date effective interaction reproduce the evolution of the 1/2 − , 3/2 − , and 5/2 − states for the neutron-rich odd-mass Cu isotopes when filling the νg 9/2 . The results indicate a significant change in the nuclear structure in this region, where a single-particle 5/2 − state coexists with more and more collective 3/2 − and 1/2 − levels at low excitation energies.

Proton radioactivity from 141 Ho and 131 Eu has been identified. The 141 Ho proton transition has an energy E p 1169͑8͒ keV, a half-life t 1͞2 4.2͑4͒ ms, and is assigned to the decay of the 7͞2 2 ͓523͔ Nilsson state. The 131 Eu transition has an energy E p 950͑8͒ keV and a half-life of 26(6) ms, consistent with decay from either the 3͞2 1 ͓411͔ or 5͞2 1 ͓413͔ Nilsson orbital. The proton decay rates deviate significantly from calculations assuming spherical configurations, and thus indicate the onset of large deformations in the region of the proton drip line below Z 69. [S0031-9007(98)