Two-quasiproton and two-quasineutron excitations in the transitional nuclei 102,104,106Pd

Abstract

Using the generalized centroid-shift method on the Rossendorf cyclotron, the half-lives of following levels were measured in the (α, 2n) reaction for the first time: T 1 2 = 1.1 ± 0.1 ns (E lev = 2294.4 keV) in 102 Pd; 0.5 ± 0.2 ns (2298.0keV), 0.40 ± 0.05 ns (3151.8keV) and 0.25 ± 0.10 ns (3368.1 keV) in 104 Pd; 2.0 ± 0.5 ns (2306.1 keV), 0.5 ± 0.1 ns (2699.3 keV), ⩽0.2 ns (2998.7 keV), 0.2 ± 0.1 ns (3289.6 keV) and 0.25 ± 0.10 ns (3461.7 keV) in 106 Pd . Further, 0.8 ± 0.2 ns (118.6 keV) in 103Pd was determined confirming an earlier result. In all three Pd isotopes, J π = 4 − states at ≈2.3 MeV are considered as two-quasiproton excitations. Two-quasineutron structures of the type ( h 11 2 d 5 2 ) and ( h 11 2 g 7 2 ) are discussed for the above-mentioned Pd isotopes and their corresponding Cd isotones revealing common features in these Z = 46 and 48 nuclei.