57 research outputs found
Generalized routhian calculations within the Skyrme-Hartree-Fock approximation
We consider here variational solutions in the Hartree-Fock approximation upon
breaking time reversal and axial symmetries. When decomposed on axial harmonic
oscillator functions, the corresponding single particle triaxial eigenstates as
functions of the usual cylindrical coordinates (r, , z) are evaluated
on a mesh in r and z to be integrated within Gauss-Hermite and Gauss-Laguerre
approaches and as Fourier decompositions in the angular variable .
Using an effective interaction of the Skyrme type, the Hartree-Fock hamiltonian
is also obtained as a Fourier series allowing a two dimensional calculation of
its matrix elements. This particular choice is shown to lead in most cases to
shorter computation times compared to the usual decomposition on triaxial
harmonic oscillator states. We apply this method to the case of the
semi-quantal approach of large amplitude collective motion corresponding to a
generalized routhian formalism and present results in the A=150 superdeformed
region for the coupling of global rotation and intrinsic vortical modes in what
is known after Chandrasekhar as the S-ellipsoid coupling case.Comment: LaTeX using elsart, 32 pages, 4 included figures, submitted to
Nuclear Physics A (revised version
Analysis of the superdefomed rotational bands
All available experimental data for the transition energies in
superdeformed bands are analyzed by using a new one-point formula. The
existence of deviations from the smooth behavior is confirmed in many bands.
However, we stress that one cannot necessarily speak about staggering patterns
as they are mostly irregular. Simulations of the experimental data suggest that
the irregularities may stem from the presence of irregular kinks in the
rotational spectra. This could be a clue but, at the moment, where such kinks
come from is an open question.Comment: 6 pages, RevTex, 7 p.s. figures, submitted to P.R.
Smooth Termination of Rotational Bands in 62Zn: Evidence for a Loss of Collectivity
Two sets of strongly coupled rotational bands have been identified in Zn-62. These bands have been observed up to the terminating states of their respective configurations. Lifetime measurements indicate that the transition quadrupole moments in these bands decrease as termination is approached. These results establish the first terminating states of rotational bands in the A similar to 60 mass region and confirm the predicted loss of collectivity associated with smooth band termination
Decay Out of the Doubly Magic Superdeformed Band in the N=Z Nucleus 60Zn
The doubly magic superdeformed band in the N = Z nucleus Zn-60 has been identified. Linking transitions connecting this band to the yrast line provide the first spin, parity, and excitation energy measurements for superdeformed states in the A similar to 60 region. The stretched-E2 character and relatively large B(E2) values of these transitions suggest a nonstatistical decay-out process
Period of the gamma-ray staggering in the 150Gd superdeformed region
It has been previously proposed to explain gamma-ray staggerings in the
deexcitation of some superdeformed bands in the Gd region in terms of a
coupling between global rotation and intrinsic vortical modes. The observed
4 period for the phenomenon is suggested from our microscopic Routhian
calculations using the Skyrme SkM* effective interaction.Comment: 4 pages, LaTeX with RevTeX, 4 included figures, submitted to Phys.
Rep. C (revised version
The Sudbury Neutrino Observatory
The Sudbury Neutrino Observatory is a second generation water Cherenkov
detector designed to determine whether the currently observed solar neutrino
deficit is a result of neutrino oscillations. The detector is unique in its use
of D2O as a detection medium, permitting it to make a solar model-independent
test of the neutrino oscillation hypothesis by comparison of the charged- and
neutral-current interaction rates. In this paper the physical properties,
construction, and preliminary operation of the Sudbury Neutrino Observatory are
described. Data and predicted operating parameters are provided whenever
possible.Comment: 58 pages, 12 figures, submitted to Nucl. Inst. Meth. Uses elsart and
epsf style files. For additional information about SNO see
http://www.sno.phy.queensu.ca . This version has some new reference
High-spin states in the mirror nuclei Ca and K
High-spin states of the mass mirror pair K
and Ca were investigated via the fusion-evaporation reaction
Si+O at 125 MeV beam energy. The Gammasphere array in
conjunction with the charged-particle detector array Microball
and neutron detectors was used to detect rays in coincidence with
evaporated light particles. The results of the first high-spin study of
the nucleus Ca are discussed in terms of mirror symmetry
and compared to spherical shell-model calculations in the
– configuration space
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