Isomerism in Ag-96 and non-yrast levels in Pd-96 and Rh-95, studied in decay

The beta decay of Ag-96 (Z = 47, N = 49) was investigated by measuring positrons, X rays as well as beta-delayed protons and gamma rays. The gamma radiation was studied by means of germanium detectors and a NaI total-absorption spectrometer. Two beta-decaying isomers in Ag-96 were established with half-lives of 4.40(6) and 6.9(6) s and tentative spin-parity assignments of (8(+)) and (2(+)), respectively. For both isomers, the intensities of beta transitions to low-lying levels of Pd-96 (Z = 46, N = 50) and beta-delayed proton decays to levels in Rh-95 (Z = 45, N = 50) were measured. Several new Pd-96 levels were firmly established. The level energies, their gamma decays and the Gamow-Teller decay of Ag-96 are compared to shell-model predictions. A new low-lying level in Rh-95 was found at 680 keV excitation energy. Through a comparison with low-lying states of N = 50 isotones, this level is interpreted as the first excited 7/2(+) state built on the proton 9/2(+) ground state. The assignments of further excited states in Rh-95 are discussed. (C) 2003 Elsevier Science B.V. All rights reserved.