Enhanced E1 transition between weakly-bound excited states in the nucleus 27Ne

Abstract

Inspired by the recently-reported strong electric-dipole (E1) transition between the weakly-bound first and second excited states, 3/2- at 765 keV and 1/2+ at 885 keV, in the nucleus 27Ne, the E1 transition is estimated in a model by properly taking into account the effect of both deformation and weakly-bound neutrons. In addition to both the spin-parities, 1/2+ and 3/2-, and observed nearly degenerate energies of the two excited states, the observed order of magnitude of the E1 transition strength between the two states is very naturally explained in the case that these two excited states are prolately deformed, in terms of the transitions between the halo components of the wave functions of the weakly-bound odd-neutrons, s1/2 -> p3/2 and s1/2 -> p1/2, in addition to the large probability of the p3/2 component in the weakly-bound neutron [330 1/2] orbit. The large probability is the result of the shell-structure unique in weakly-bound or resonant neutrons.

6 figures, 2 tables

References in corpus (5)

• Nilsson diagrams for light neutron-rich nuclei with weakly-bound neutrons
• Interpretation of Coulomb breakup of 31Ne in terms of deformation
• Neutron shell structure and deformation in neutron-drip-line nuclei
• Properties of 12Be and 11Be in terms of single-particle motion in deformed potential
• Shape and shell-structure of lighter (N<90) neutron-rich nuclei based on phenomenological Woods-Saxon potential

Cited by in corpus (1)

• Deformed Halo of ^{29}_{9}F_{20}