The lifetime of the proton-decaying 8915 keV state in 58Cu

Isospin and deformation studies in the odd-oddN=ZnucleusCo54

“…The first option concerns particle decays competing with γ -ray emission from both deformed or spherical high-spin states. Indeed, discrete-energy proton and α "linking transitions" between well-deformed rotational states in the mother nucleus and near-spherical states in the respective daughter nucleus have been observed in nearby nuclei, e.g., proton decays from bands in 56 Ni [3,45] and 58 Cu [23,46], or α decays from two rotational states in 58 Ni [47,48], while principally, of course, any excited state above particle threshold may exhibit particle decay branches, deformed or not. For instance, in case of rotational bands populated via fusion-evaporation reactions, this has been studied by Døssing and coworkers [49], while the hindrance factor induced for the specific proton decay from the deformed band in 58 Cu [46] has been explained by a combination of the change of the nuclear shape and the change of the K quantum number of a 1g 9/2 neutron "spectator" [50].…”

Exotic Decay Modes in Rotating Nuclei

“…The focus has been on 58 Cu, where spins and parities of the initial and final state could be assigned [5,8,9] and lifetimes of γ-and proton-decaying states have been measured in the decay-out regime of the rotational band [5,10] ? Figure 1.…”

High-spin proton emitters in odd-odd nuclei and shape changes

“…The initial K-value of 58 Cu is given by K i = |K π ± K ν | yielding a value of K i = 1, 0. If one assumes that the daughter (final) nucleus 57 Ni has the same prolate deformation as 58 Cu the overlap is unity and the half-live becomes T ≈ 0.8 × 10 −16 s, which underestimates the corresponding experimental value, i. e. T exp ≈ 0.5 × 10 −12 s [21], by four orders of magnitude.…”

“…In addition, we investigate the role played by the angular momentum orientation of the odd particle in the intrinsic system. As an example we will consider the case of 58 Cu, which life time has been established recently [21].…”