Abstract
The shell closure has been investigated via the transfer reaction in inverse kinematics. Energies and spectroscopic factors of the neutron , , and states in were determined and compared to those of the isotone. We deduced a reduction of the gap by 330(90) keV and spin-orbit weakenings of and 45(10)% for the and states, respectively. Such large variations for the and spin-orbit splittings could be accounted for by the proton-neutron tensor force and by the density dependence of the spin-orbit interaction, respectively. This contrasts with the picture of the spin-orbit interaction as a surface term only.
- Received 6 April 2006
DOI:https://doi.org/10.1103/PhysRevLett.97.092501
©2006 American Physical Society