352 research outputs found
Linear response theory in the continuum for deformed nuclei: Green's function vs. time-dependent Hartree-Fock with the absorbing-boundary condition
The continuum random-phase approximation is extended to the one applicable to
deformed nuclei. We propose two different approaches. One is based on the use
of the three dimensional (3D) Green's function and the other is the
small-amplitude TDHF with the absorbing-boundary condition. Both methods are
based on the 3D Cartesian grid representation and applicable to systems without
any symmetry on nuclear shape. The accuracy and identity of these two methods
are examined with the BKN interaction. Using the full Skyrme energy functional
in the small-amplitude TDHF approach, we study the isovector giant dipole
states in the continuum for O-16 and for even-even Be isotopes.Comment: 15 pages, 8 figure
Removal of Spurious Admixture in a Self-consistent Theory of Adiabatic Large Amplitude Collective Motion
In this article we analyse, for a simple model, the properties of a practical
implementation of a fully self-consistent theory of adiabatic large-amplitude
collective motion using the local harmonic approach. We show how we can deal
with contaminations arising from spurious modes, caused by standard simplifying
approximations. This is done both at zero and finite angular momentum. We
analyse in detail the nature of the collective coordinate in regions where they
cross spurious modes and mixing is largest
N-Body Nuclear Forces at Short Distances in Holographic QCD
We provide a calculation of N-body (N>2) nucleon interactions at short
distances in holographic QCD. In the Sakai-Sugimoto model of large N_c massless
QCD, N baryons are described by N Yang-Mills instantons in 5 spacetime
dimensions. We compute a classical short distance interaction hamiltonian for N
'tHooft instantons. This corresponds to N baryons sharing identical classical
spins and isospins. We find that genuine N-body nuclear forces turn out to
vanish for N>2, at the leading order. This suggests that classical N-body
forces are always suppressed compared with 2-body forces.Comment: 4 page
Dipole responses in Nd and Sm isotopes with shape transitions
Photoabsorption cross sections of Nd and Sm isotopes from spherical to
deformed even nuclei are systematically investigated by means of the
quasiparticle-random-phase approximation based on the Hartree-Fock-Bogoliubov
ground states (HFB+QRPA) using the Skyrme energy density functional. The
gradual onset of deformation in the ground states as increasing the neutron
number leads to characteristic features of the shape phase transition. The
calculation well reproduce the isotopic dependence of broadening and emergence
of a double-peak structure in the cross sections without any adjustable
parameter. We also find that the deformation plays a significant role for
low-energy dipole strengths. The strengths are fragmented and considerably
lowered in energy. The summed strength up to 10 MeV is enhanced by a
factor of five or more.Comment: 5 pages including 6 figure
Absorbing Boundary Condition Approach for Breakup Reactions of Halo Nuclei
Application of the absorbing boundary condition is discussed to analyse breakup reactions of weakly bound nuclei. The key ingredient is an introduction of the absorbing potential outside the physical area which simulates the outgoing boundary condition approximately. The scattering problem is then recasted into the Schroedinger like equation with a source term in the interaction region and with the vanishing boundary condition at the boundary. We demonstrate usefulness of the method taking a few examples. Deuteron breakup reactions are examined comparing present results with those by the continuum-discretized coupled-channel method. We next discuss the breakup reactions of single-neutron halo nucleus, 11Be
Fusion reaction of halo nuclei: A real-time wave-packet method for three-body tunneling dynamics
We investigate fusion cross section of a nucleus with a valence neutron,
using the time-dependent wave-packet method. For a stable projectile, in which
the valence neutron is tightly bound (e_n < -3 MeV), the neutron could enhance
the fusion probability when the matching condition of orbital energies are
satisfied. In contrast, for a halo nucleus, in which the binding energy of the
neutron is very small (e_n>-1 MeV), the fusion probability is hindered by the
presence of the weakly bound neutron.Comment: Talk at Internaitonal Conference on "Reaction Mechanisms and Nuclear
Structure at the Coulomb Barrier" (FUSION06), Venice, Italy, March 19-23,
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