Gamow®CTeller (GT) states in N = Z nuclei with the mass number A from 48 to 64 are studied by using Hartree®CFock®CBogoliubov + quasi-particle random phase approximation ( \HFB\ + \QRPA\ ) with Skyrme interactions. The isoscalar spin-triplet ( T =

Energy-dependent phenomenological optical model potentials based on a single-folding model approach for the α- 12 C and deuteron- 12 C systems were obtained for incident energies between 10 and 100 MeV/nucleon. The Lane-consistent Bruyères Jeukenne–Lejeune–Mahaux model nucleon–nucleus potentials were used in these calculations. With only three free parameters, these potentials account satisfactorily for both angular distributions of elastic scattering cross sections and total reaction cross sections of both projectile–target systems within the energy range studied. Comparisons were made between the present potentials and other systematic phenomenological potentials.

Configuration-constrained potential energy surface calculations have been performed to investigate four-quasiparticle high- K configurations in neutron-deficient lead and polonium isotopes. A good agreement between the calculations and the experimental data has been found for the excitation energy of the observed K π = 19 − state in 188 Pb. Several lowly excited high- K states are predicted, and the large oblate deformation and low energy indicate high- K isomerism in these nuclei.

The fission of high- K , two-quasiparticle isomers is considered, with specific reference to 250 No, 254 No and 256 Fm. The published experimental evidence is discussed in relation to configuration-constrained potential-energy-surface calculations, which suggest that the high- K isomers should be less susceptible to fission than their corresponding ground states.

Full shell-model diagonalization has been performed to study the structure of neutron-rich nuclei around 20C. We investigate in detail the roles played by the different monopole components of the effective interaction in the evolution of the N = 14 shell in C, N and O isotopes. It is found that the relevant neutron–neutron monopole terms, V d 5 / 2 d 5 / 2 n n and V s 1 / 2 s 1 / 2 n n , contribute significantly to the reduction of the N = 14 shell gap in C and N isotopes in comparison with that in O isotopes. The origin of this unexpectedly large effect, which is comparable with (sometimes even larger than) that caused by the proton–neutron interaction, is related to the enhanced configuration mixing in those nuclei due to many-body correlations. Such a scheme is also supported by the large B ( E 2 ) value in the nucleus 20C which has been measured recently.