2,364 research outputs found
Excited-State Density Distributions of Neutron-Rich Unstable Nuclei
We calculate densities of excited states in the quasiparticle random-phase
approximation (QRPA)with Skyrme interactions and volume pairing. We focus on
low-energy peaks/bumps in the strength functions of a range of Ca, Ni, and Sn
isotopes for J pi = 0+, 1-, and 2+. We define an "emitted-neutron number",
which we then use to distinguish localized states from scattering-like states.
The degree of delocalization either increases as the neutron-drip line is
approached or stays high between the stability line and the drip line. In the
2+ channel of Sn, however, the low-lying states, not even counting surface
vibrations, are still fairly well localized on average, even at the neutron
drip line.Comment: 4 pages, 4 figure
Non-factorizable contribution in nonleptonic weak interactions of K mesons
Two pion decays of K mesons, K_L-K_S mass difference, two photon and the
Dalitz decays of K_L are studied systematically by assuming that their
amplitude is given by a sum of factorizable and non-factorizable ones. The
former is estimated by using a naive factorization while the latter is assumed
to be dominated by dynamical contributions of various hadron states.Comment: 23 pages,1 figur
Overlap of quasiparticle random-phase approximation states for nuclear matrix elements of the neutrino-less double beta decay
Quasiparticle random-phase approximation (QRPA) is applied to two nuclei, and
overlap of the QRPA excited states based on the different nuclei is calculated.
The aim is to calculate the overlap of intermediate nuclear states of the
double-beta decay. We use the like-particle QRPA after the closure
approximation is applied to the nuclear matrix elements. The overlap is
calculated rigorously by making use of the explicit equation of the QRPA ground
state. The formulation of the overlap is shown, and a test calculation is
performed. The effectiveness of the truncations used is shown.Comment: 3 minor corrections and 1 minor chang
Charmed scalar resonances -- Conventional and four-quark mesons
We propose that there coexist two scalar mesons of different structures (a
conventional meson and a four-quark meson) in the recently observed broad bumps
just below the large peak of the tensor meson in the D-pi mass distribution. We
base this proposal on the interpretation of the charm-strange scalar meson of
mass 2317 MeV as a four-quark meson. The strange counterparts of these scalar
mesons are also studied.Comment: 4 pages, 0 figures, Revte
Onset of T=0 Pairing and Deformations in High Spin States of the N=Z Nucleus 48Cr
The yrast line of the N=Z nucleus 48Cr is studied up to high spins by means
of the cranked Hartree-Fock-Bogoliubov method including the T=0 and T=1 isospin
pairing channels. A Skyrme force is used in the mean-field channel together
with a zero-range density-dependent interaction in the pairing channels. The
extensions of the method needed to incorporate the neutron-proton pairing are
summarized. The T=0 pairing correlations are found to play a decisive role for
deformation properties and excitation energies above 16hbar which is the
maximum spin that can be obtained in the f7/2 subshell.Comment: LaTeX, 4 ps figure
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