Di-neutron correlation and soft dipole excitation in medium mass neutron-rich nuclei near drip line
- Graduate School of Science and Technology, Niigata University, Niigata 950-2181 (Japan)
The neutron pairing correlation and the soft dipole excitation in medium mass nuclei near the drip line are investigated from the viewpoint of the di-neutron correlation. Numerical analyses based on the coordinate-space Hartree-Fock-Bogoliubov method and the continuum quasiparticle random phase approximation are performed for even-even {sup 18-24}O,{sup 50-58}Ca, and {sup 80-86}Ni. A clear signature of the di-neutron correlation is found in the ground state; two neutrons are correlated at short relative distances < or approx. 2 fm with large probability {approx}50%. The soft dipole excitation is influenced strongly by the neutron pairing correlation, and it accompanies a large transition density for pair motion of neutrons. This behavior originates from a coherent superposition of two-quasiparticle configurations [lx(l+1)]{sub L=1} consisting of continuum states with high orbital angular momenta l reaching an order of l{approx}10. It suggests that the soft dipole excitation under the influence of neutron pairing is characterized by the motion of di-neutron in the nuclear exterior against the remaining A-2 subsystem. Sensitivity to the density dependence of the effective pair force is discussed.
- OSTI ID:
- 20698754
- Journal Information:
- Physical Review. C, Nuclear Physics, Vol. 71, Issue 6; Other Information: DOI: 10.1103/PhysRevC.71.064326; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2813
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CALCIUM 50
CALCIUM 51
CALCIUM 52
CALCIUM 53
CORRELATIONS
DIPOLES
EXCITATION
GROUND STATES
HARTREE-FOCK METHOD
HARTREE-FOCK-BOGOLYUBOV THEORY
NEUTRON-RICH ISOTOPES
NEUTRONS
NICKEL ISOTOPES
NUCLEAR FORCES
NUMERICAL ANALYSIS
ORBITAL ANGULAR MOMENTUM
OXYGEN 18
OXYGEN 20
OXYGEN 24
PROBABILITY
RANDOM PHASE APPROXIMATION