LEVELS IN ${}_{38}^{80}{\rm Sr}$, ${}_{39}^{83}{\rm Y}$ AND ${}_{40}^{83}{\rm Zr}$ AND THE NEW REGION OF STRONG DEFORMATION AROUND N=Z≈38

1988 ◽  
Vol 03 (02) ◽  
pp. 499-505 ◽  
Author(s):  
A.V. RAMAYYA ◽  
M.A. HERATH-BANDA ◽  
M. BARCLAY ◽  
J.H. HAMILTON ◽  
W.C. MA ◽  
...  
Keyword(s):  
Large Deformation ◽  
Ground State ◽  
Energy Levels ◽  
Heavy Ion ◽  
Research Facility ◽  
Max Planck ◽  
Ground State Band ◽  
State Band ◽  
Γ Ray ◽  
Strong Deformation

The energy levels in [Formula: see text] and [Formula: see text] were identified and investigated along with 80 Sr via in-beam γ-ray spectroscopy to explore the new region of strong deformation centered around N=Z=38. The reaction 51 V (32 S , p2n)80 Sr was studied at the Holifield Heavy Ion Research Facility and reactions 54 Fe (32 S , α2p)80 Sr ; 54 Fe (32 S , 3p)83 Y and 54 Fe (32 S , 2pn)83 Zr at the Max Planck Tandem. The deformation in the ground state band in 80 Sr observed to 12+ shows a significant increase as N decreases toward 38. A 9/2+ ground state band in [Formula: see text] observed to (29/2+) exhibits larger deformation than an excited (9/2+) band in [Formula: see text] as expected as Z moves away from 38. These nuclei support the proposal that the large deformation observed in this region arises from the reinforcing of the proton and neutron shape driving force as both N and Z approach shell gaps at large deformation for N and Z of 38.

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.

The 12 C(γ, 3α) reaction energy levels of 8 Be and 12 C

1955 ◽  
Vol 228 (1174) ◽  
pp. 376-396 ◽  
Keyword(s):  
Ground State ◽  
Energy Levels ◽  
Electric Quadrupole ◽  
Angular Distributions ◽  
Reaction Energy ◽  
Reaction Proceeds ◽  
Γ Ray ◽  
Relationship Of ◽  
The Relationship ◽  
Α Particles

The mechanism of the 12 C(γ, 3α) reaction, for γ-ray energies, E γ , up to about 40 MeV, has been determined from a study of over 2500 stars in nuclear emulsions. The study includes investigation of the angular distributions and correlations of the α-particles. The reaction is initiated mainly by electric-dipole and electric-quadrupole γ-ray interaction, the former being unexpectedly strong when E γ < 20 MeV. For E γ < 25 MeV the reaction proceeds mainly by transitions to the ground-state of 8 Be (spin J = 0), and to 2⋅95 ± 0⋅10 MeV ( J = 2) and 4⋅0 ± 0⋅1 MeV ( J = 2 or 4) levels of 8 Be. Transitions to levels near 6, 10 and 15 MeV (all J = 0, 2 or 4) become predominant when 25 MeV ≤ E γ <26 MeV. For E γ ≥ 26 MeV, most transitions lead to 16⋅8 ± 0⋅2 MeV ( J = 2) and 17⋅6 ± 0⋅2 MeV ( J = 2, possibly 0) levels, and possibly to a further 16⋅4 ± 0⋅2 MeV ( J = 0 or 2) level, levels which have not been detected in other reactions. The reaction mechanism is interpreted in terms of competing modes of decay of a compound nucleus, demonstrating the strong influence of the isotopic spins ( T ) of the levels of 12 C and 8 Be involved. For example, the 2 + levels of 12 C involved when 16 MeV ≤ E γ <20 MeV are (unexpectedly) found to have T = 1, and the 16⋅8 and 17⋅6 MeV levels of 8 Be are also found to have T = 1. The relationship of the 12 C (γ, 3α) reaction to other 12 C photodisintegration reactions (including some new reactions established during the present experiments) is discussed.

Rotation-particle coupling in the ground state band of 161Dy

1972 ◽  
Vol 184 (1) ◽  
pp. 113-137 ◽  
Author(s):  
S.A. Hjorth ◽  
A. Johnson ◽  
G. Ehrling
Keyword(s):  
Ground State ◽  
Ground State Band ◽  
State Band
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