3 research outputs found
Pairing transition of nuclei at finite temperature
Pairing transition at finite temperature was investigated by the shell model
and BCS calculations. The definitive signature of pairing transition is
identified by a "transition temperature" estimated from a "thermal"
odd-even mass difference, while there is no sharp phase transition because of
the finiteness of nucleus. It is found that is in good agreement with
predictions of critical temperature in the BCS approximation, and the
pairing correlations almost vanish at two points of the transition temperature
. The BCS calculations show that the critical temperature
increases with increasing deformation.Comment: 12 pages, 6 figures, accepted for publication in Nuclear Physics
Effects of resonant single-particle states on pairing correlations
Effects of resonant single-particle (s.p.) states on the pairing correlations
are investigated by an exact treatment of the pairing Hamiltonian on the Gamow
shell model basis. We introduce the s.p. states with complex energies into the
Richardson equations. The solution shows the property that the resonant s.p.
states with large widths are less occupied. The importance of many-body
correlations between bound and resonant prticle pairs is shown.Comment: 4 pages, 3 figures, to be published in Phys. Rev.