scholarly journals g-factors of some excited states in 49,50Cr

2019 ◽  
Vol 3 ◽  
pp. 205
Author(s):  
A. A. Pakou ◽  
J. Billowes ◽  
A. W. Mountford ◽  
C. Tenreiro ◽  
D. D. Warner
Keyword(s):  
Magnetic Field ◽  
Excited States ◽  
Ground State ◽  
Experimental Error ◽  
Magnetic Moments ◽  
Transient Field ◽  
Ground State Band ◽  
Model Calculations ◽  
State Band ◽  
G Factors

Magnetic moments of the first excited states in 50Cr and of the 7/2" and 19/2' states in 49Cr, have been measured by the transient field technique. The states were excited by the inverse reaction 40Ca + 12C and the recoil nuclei traversed a thick gadolinium foil. The observed rotations, of the 2+, 4+, 6+, 8+ states of the ground-state band in 50Cr, were found into the experimental error to be the same, suggesting similar g-factors for these states and thus supporting a high collectivity for the ground-state band, g-factors of the 7/2' and 19/2 states in 49Cr, were deduced by adopting both an overall parametrization of the transient magnetic field in Gd and by comparing the 49Cr rotations with rotations of states with known magnetic moments, as the 2+ ones of 50Cr and of 46Ti which was also populated in the same reaction. Both methods gave similar results and the g-factors adopted for the 19/2" and 7/2" states were + 0.78(17) and +0.35(7) respectively. These results are discussed in terms of cranked shell model calculations and are found to support a proton alignment in the f7/2 shell.

scholarly journals Study of the Q.Q interaction

2018 ◽  
Vol 27 (07) ◽  
pp. 1850056
Author(s):  
Arun Kingan ◽  
Xiaofei Yu ◽  
Larry Zamick
Keyword(s):  
Shell Model ◽  
Quadrupole Interaction ◽  
Single Particle ◽  
Ground State ◽  
Ground State Band ◽  
Rotational Model ◽  
Model Calculations ◽  
State Band

We perform shell model calculations using a quadrupole–quadrupole interaction (Q.Q). We show results in single j shell spaces and the full S-D shell. We show that one gets useful results with Q.Q in both spaces. We emphasize the importance of the choice of single particle energies in order to obtain the results of Elliott using a Q.Q interaction without the momentum terms. We show a [Formula: see text] spectrum for a ground state band but with [Formula: see text]’s different from the rotational model. We also show results such as [Formula: see text] and [Formula: see text] excited “spin bands”. (The latter can also be expressed as a [Formula: see text] band). We find spectra starting with [Formula: see text] which have both even [Formula: see text] and odd [Formula: see text] members.

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.

scholarly journals Wigner SU(4) symmetry, clustering, and the spectrum of $$^{12}$$C

2021 ◽  
Vol 57 (9) ◽  
Author(s):  
Shihang Shen ◽  
Timo A. Lähde ◽  
Dean Lee ◽  
Ulf-G. Meißner
Keyword(s):  
Excited States ◽  
Ground State ◽  
Nucleon Nucleon ◽  
Irreducible Representations ◽  
Spin Orbit ◽  
Hoyle State ◽  
Nucleon Interaction ◽  
Model Calculations ◽  
Nucleon Nucleon Interaction ◽  
Spin Orbit Interactions

AbstractWe present lattice calculations of the low-lying spectrum of $$^{12}$$ 12 C using a simple nucleon–nucleon interaction that is independent of spin and isospin and therefore invariant under Wigner’s SU(4) symmetry. We find strong signals for all excited states up to $$\sim 15$$ ∼ 15  MeV above the ground state, and explore the structure of each state using a large variety of $$\alpha $$ α cluster and harmonic oscillator trial states, projected onto given irreducible representations of the cubic group. We are able to verify earlier findings for the $$\alpha $$ α clustering in the Hoyle state and the second $$2^+$$ 2 + state of $$^{12}$$ 12 C. The success of these calculations to describe the full low-lying energy spectrum using spin-independent interactions suggest that either the spin-orbit interactions are somewhat weak in the $$^{12}$$ 12 C system, or the effects of $$\alpha $$ α clustering are diminishing their influence. This is in agreement with previous findings from ab initio shell model calculations.

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
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