scholarly journals W(5): Wobbling Mode in the Framework of the X(5) Model

2020 ◽  
Vol 13 ◽  
pp. 214
Author(s):  
Dennis Bonatsos ◽  
D. Lenis ◽  
D. Petrellis ◽  
P. A. Terziev
Keyword(s):  
Ground State ◽  
Transition Rates ◽  
Ground State Band ◽  
Sharp Minimum ◽  
Scale Factors ◽  
State Band

Using in the Bohr Hamiltonian the approximations leading to the Bohr and Mot- telson description of wobbling motion in even nuclei, a W(5) model for wobbling bands, coexisting with a X(5) ground state band, is obtained. Separation of vari­ ables is achieved by assuming that the relevant potential has a sharp minimum at 70, which is the only parameter entering in the spectra and B(E2) transition rates (up to overall scale factors). B(E2) transition rates exhibit the features expected in the wobbling case.

scholarly journals γ-rigid solution of the Bohr Hamiltonian compared to the E(5) critical point symmetry

2019 ◽  
Vol 14 ◽  
pp. 71
Author(s):  
Dennis Bonatsos ◽  
D. Lenis ◽  
D. Petrellis ◽  
P. Terziev ◽  
I. Yigitoglu
Keyword(s):  
Critical Point ◽  
Ground State ◽  
Close Agreement ◽  
Point Symmetry ◽  
Transition Rates ◽  
Ground State Band ◽  
Scale Factors ◽  
State Band ◽  
Euclidean Algebra ◽  
Rigid Solution

A γ-rigid solution of the Bohr Hamiltonian for 7 = 30° is derived, its ground state band being related to the second order Casimir operator of the Euclidean algebra E(4). Parameter-free (up to overall scale factors) predictions for spectra and B(E2) transition rates are in close agreement to the E (5) critical point symmetry, as well as to experimental data in the Xe region around A = 130.

scholarly journals Analytic description of critical point actinides in a transition from octupole deformation to octupole vibrations

2019 ◽  
Vol 14 ◽  
pp. 35
Author(s):  
Dennis Bonatsos ◽  
D. Lenis ◽  
N. Minkov ◽  
D. Petrellis ◽  
P. Yotov
Keyword(s):  
Ground State ◽  
Analytic Description ◽  
Symmetric Model ◽  
Transition Rates ◽  
Axially Symmetric ◽  
Ground State Band ◽  
Energy Data ◽  
Octupole Deformation ◽  
State Band ◽  
Band Spectra

An analytic collective model in which the relative presence of the quadrupole and octupole deformations is determined by a parameter (φο), while axial symmetry is obeyed, is developed. The model [to be called the analytic quadrupole octupole axially symmetric model (AQOA)] involves an infinite well potential, provides predictions for energy and Β (EL) ratios which depend only on φο, draws the border between the regions of octupole deformation and octupole vibrations in an essentially parameter-independent way, and describes well 2 2 6Th and 226Ra, for which experimental energy data are shown to suggest that they lie close to this border. The similarity of the AQOA results with φο = 45° for ground state band spectra and B(E2) transition rates to the predictions of the X(5) model is pointed out.

The ground state band of25Mg studied by electron scattering

1975 ◽  
Vol 1 (2) ◽  
pp. L13-L17 ◽  
Author(s):  
E W Lees ◽  
C S Curran ◽  
S W Brian ◽  
W A Gillespie ◽  
A Johnston ◽  
...  
Keyword(s):  
Electron Scattering ◽  
Ground State ◽  
Ground State Band ◽  
State Band

scholarly journals NEW STRUCTURES IN 178HF AND COULOMB EXCITATION OF ISOMERS

2011 ◽  
Vol 20 (02) ◽  
pp. 474-481 ◽  
Author(s):  
A.B. HAYES ◽  
D. CLINE ◽  
C. Y. WU ◽  
A.M. HURST ◽  
M.P. CARPENTER ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Ground State ◽  
Coulomb Excitation ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Particle Detector ◽  
Ground State Band ◽  
Rotational Bands ◽  
Coincidence Data ◽  
State Band

A 985 MeV 178 Hf beam was Coulomb excited by a 208 Pb target at the ATLAS accelerator of Argonne National Laboratory. Gammasphere and the CHICO particle detector recorded particle-γ coincidence data. The aim was to populate and determine the mechanism of previously observed Coulomb excitation of the Kπ = 6+ (t1/2 = 77 ns ), 8- (4 s ) and 16+ (31 y ) isomer bands. New rotational bands were identified including an aligned band which appears to mix with the ground-state band (GSB) and the γ-vibrational band above ~ 12 ħ of angular momentum. Newly observed γ-decay transitions into the three isomer bands may elucidate the K-mixing which allows Coulomb excitation of these isomer bands, but direct decays from the GSB into the 16+ isomer band have not yet been confirmed.

Spin Alignment of the Ground-State Band Levels in Nd and Sm Isotopes Excited in (α, 2nγ) Reactions

1972 ◽  
Vol 33 (6) ◽  
pp. 1515-1521 ◽  
Author(s):  
Hiroyasu Ejiri ◽  
Tokushi Shibata ◽  
Akira Shimizu ◽  
Kohsuke Yagi
Keyword(s):  
Ground State ◽  
Ground State Band ◽  
Spin Alignment ◽  
State Band

scholarly journals Variational procedure leading from Davidson potentials to the E(5)and X(5) critical point symmetries

2020 ◽  
Vol 13 ◽  
pp. 10
Author(s):  
Dennis Bonatsos ◽  
D. Lenis ◽  
N. Minkov ◽  
D. Petrellis ◽  
P. P. Raychev ◽  
...  
Keyword(s):  
Phase Transition ◽  
Critical Point ◽  
Ground State ◽  
Nuclear Energy ◽  
Energy Spectra ◽  
Variational Procedure ◽  
Ground State Band ◽  
Sharp Maximum ◽  
State Band ◽  
Shape Phase Transition

Davidson potentials of the form β^2 + β0^4/β^2, when used in the original Bohr Hamiltonian for γ-independent potentials bridge the U(5) and 0(6) symmetries. Using a variational procedure, we determine for each value of angular momentum L the value of β0 at which the derivative of the energy ratio RL = E(L)/E(2) with respect to β0 has a sharp maximum, the collection of RL values at these points forming a band which practically coincides with the ground state band of the E(5) model, corresponding to the critical point in the shape phase transition from U(5) to Ο(6). The same potentials, when used in the Bohr Hamiltonian after separating variables as in the X(5) model, bridge the U(5) and SU(3) symmetries, the same variational procedure leading to a band which practically coincides with the ground state band of the X(5) model, corresponding to the critical point of the U(5) to SU(3) shape phase transition. A new derivation of the Holmberg-Lipas formula for nuclear energy spectra is obtained as a by-product.

Ground-state band inSe72

1977 ◽  
Vol 15 (3) ◽  
pp. 939-949 ◽  
Author(s):  
K. P. Lieb ◽  
J. J. Kolata
Keyword(s):  
Ground State ◽  
Ground State Band ◽  
State Band

scholarly journals Konversionselektronen von 156Gd nach Neutroneneinfang / The Conversion Electron Spectrum of the Reaction 155Gd(n,e)156Gd

1974 ◽  
Vol 29 (1) ◽  
pp. 17-30
Author(s):  
K. Schreckenbach
Keyword(s):  
Ground State ◽  
Conversion Electron ◽  
Electron Spectrum ◽  
Vibrational Band ◽  
Ground State Band ◽  
Conversion Electron Spectrum ◽  
State Band

The conversion electron spectrum of the reaction 155Gd (n, e) 156Gd has been measured up to 8.5 MeV. The results below 4.5 MeV are presented and multipolarities are determined with these results. E0 admixtures of the Δ I = 0 transitions from the 0 + β-vibrational band to the ground state band were determined with 15% accuracy. 156Gd level schemes are discussed and extended by new spin and parity assignments.

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