© 2019 American Physical Society. The superfluid tunneling model is applied to the calculation of half-lives of the observed α decays in N=84 isotones. Results of our calculations are compared to experimental data on the ground-state α decays along the isotonic chain from Nd144 to Re159. Good agreement is found. The α decays of the known high-spin isomers in Lu155, Hf156, Ta157, and W158 are also well reproduced, once a reduction in the pairing strength is taken into account. This includes reproduction of the main features of the recently observed fine structure from Lu155(25/2-) and Hf156(8+). Predictions for the α-decay fine structure of Ta157(25/2-) and W158(8+) high-spin isomers are presented.

© 2020 American Physical Society. The superfluid tunneling model is applied to the calculation of ground-state-to-ground-state α decay in the even-even neutron-deficient Te-Ba nuclei. We show that there is a larger α-particle formation probability in nuclei of this region above Sn100 when compared to analogous nuclei above Pb208. This is consistent with the expected systematic variation of the pair gap Δ as a function of mass number. The recent experimental data on the α decay of the N=Z nuclei Te104 and Xe108 are shown to leave open the possibility of enhanced α-particle formation involving nucleon correlations beyond the standard treatment of like-nucleon pairing, which is the mechanism suggested as underlying "superallowed" α decay.

© 2017 The Authors Recent results from RIKEN/RIBF on the low-lying level structure of 29F are interpreted within the Particle-Rotor Model. We show that the experimental data can be understood in the Rotation-aligned Coupling Scheme, with the 5/2+ ground state as the bandhead of a decoupled band. In this picture, the energy of the observed 1/21+ state correlates strongly with the rotational energy of the core and provides an estimate of the 2+ energy in 28O. Our analysis suggests a moderate deformation, ϵ2∼0.16, and places the 2+ in 28O at ∼ 2.5 MeV.

© 2017 American Physical Society. Spectroscopic factors, extracted from one-neutron knockout and Coulomb dissociation reactions, for transitions from the ground state of Mg33 to the ground-state rotational band in Mg32, and from Mg32 to low-lying negative-parity states in Mg31, are interpreted within the rotational model. Associating the ground state of Mg33 and the negative-parity states in Mg31 with the 32[321] Nilsson level, the strong coupling limit gives simple expressions that relate the amplitudes (Cjℓ) of this wave function with the measured cross sections and derived spectroscopic factors (Sjℓ). To obtain a consistent agreement with the data within this framework, we find that one requires a modified 32[321] wave function with an increased contribution from the spherical 2p3/2 orbit as compared to a standard Nilsson calculation. This is consistent with the findings of large-scale shell model calculations and can be traced to weak binding effects that lower the energy of low-ℓ orbitals.

© 2018 American Physical Society. Spectroscopic factors in Be10, Be11, and Be12, extracted from (d,p), one-neutron knockout, and (p,d) reactions, are interpreted within the rotational model. Assuming that the ground state and first excited state of Be11 can be associated with the 12[220] and 12[101] Nilsson levels, the strong-coupling limit gives simple expressions that relate the amplitudes of these wave functions (in the spherical basis) with the measured cross sections and derived spectroscopic factors. We obtain good agreement with both the measured magnetic moment of the ground state in Be11 and the reaction data.