Abstract
The masses of and have been determined with the Penning-trap mass spectrometer ISOLTRAP at the ISOLDE facility at CERN, including the previously unknown mass and half-life of . We study the evolution of the odd-even staggering of binding energies along the francium and radium isotopic chains and of its lowest-order estimator, . An enhancement of the staggering of is observed towards neutron number , which points to contributions beyond pairing correlations. These contributions are investigated in the Hartree-Fock and Hartree-Fock-Bogoliubov approaches, emphasizing the connections to the single-particle level density and nuclear deformation.
- Received 28 May 2014
DOI:https://doi.org/10.1103/PhysRevC.90.024301
©2014 American Physical Society