Di-neutron correlation and soft dipole excitation in medium mass neutron-rich nuclei near drip line

Journal Article · Wed Jun 01 04:00:00 EDT 2005 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PhysRevC.71.064326· OSTI ID:20698754

Matsuo, Masayuki; Mizuyama, Kazuhito; Serizawa, Yasuyoshi ^[1]

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1. 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, Journal Name: Physical Review. C, Nuclear Physics Journal Issue: 6 Vol. 71; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
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