NEW 5− AND 6+ STATES IN Ne20

1964 ◽  
Vol 42 (3) ◽  
pp. 477-488 ◽  
Author(s):  
J. A. Kuehner ◽  
J. D. Pearson
Keyword(s):  
Excited States ◽  
Rotational Band ◽  
Ground State ◽  
Negative Parity ◽  
Alpha Particles ◽  
Excitation Energies ◽  
Angular Correlations ◽  
Fourth Member

Excited states of Ne20 at excitation energies of 8.46 Mev and 8.79 Mev have been identified and assigned spin and parity values of 5− and 6+, respectively. The excited states were produced in the C12(C12, α)Ne10 reaction and the spin assignments were made on the basis of angular correlations of the decay alpha particles from these states leaving O16 in its ground state. It is postulated that the 5− state is the fourth member of a K = 2 negative-parity rotational band based on the 2– 4.97-Mev state and that the 6+ state is the fourth member of a K = 0 rotational band based on the 0+ ground state of Ne20.

THE 6He+6He AND α+8He CLUSTER STATES IN 12Be VIA α-INELASTIC SCATTERING

2010 ◽  
Vol 25 (21n23) ◽  
pp. 1858-1861 ◽  
Author(s):  
A. SAITO ◽  
S. SHIMOURA ◽  
T. MINEMURA ◽  
Y. U. MATSUYAMA ◽  
H. BABA ◽  
...  
Keyword(s):  
Excitation Energy ◽  
Inelastic Scattering ◽  
Excited States ◽  
Rotational Band ◽  
Cluster Structure ◽  
Decomposition Analysis ◽  
Incident Beam ◽  
Negative Parity ◽  
Angular Correlations ◽  
Measured Momentum

Cluster structures in the neutron-rich nucleus 12 Be were experimentally investigated via α-inelastic scattering. Excited states in the 12 Be nucleus were populated by a 12 Be (αα') reaction at 60 A MeV in the inverse kinematics, and identified by measuring a 6 He +6 He and α+8 He breakup channels in coincidence. The differential cross section and the angular correlations between the decay particles were obtained for each excitation energy at 10–20 MeV for 6 He +6 He and at 9–19 MeV for α+8 He , respectively, reconstructed by the measured momentum vectors of the two helium isotopes. A multipole decomposition analysis based on the distorted-wave Born approximation was applied for the angular distribution of the inelastic scattering together with the angular correlation between the decay particles with respect to the directions of the incident beam and to the momentum transfer simultaneously. From the decomposed excitation energy spectra for J=0-4, several new excited states were identified. The 0+ excited states were candidates of the band-head of a largely deformed rotational band. The 11.3-MeV 0+ state was found to decay only into the 6 He +6 He channel. This result support the recent theoretical result by the generalized two-center cluster model. Several negative-parity excited states were observed in the α+8 He channel. These excited states possibly forming a negative-parity rotational band, which is very closed to the positive-parity band, can be connected to the existence of the extremely developed cluster structure in 12 Be .

AN INTERPRETATION OF THE LOW-LYING EXCITED STATES OF Mg25 AND Al25

1958 ◽  
Vol 36 (3) ◽  
pp. 378-404 ◽  
Author(s):  
A. E. Litherland ◽  
H. McManus ◽  
D. A. Bromley ◽  
H. E. Gove ◽  
E. B. Paul
Keyword(s):  
Excited States ◽  
Ground State ◽  
Salient Feature ◽  
Negative Parity ◽  
State Transitions ◽  
Rotational Model ◽  
Rotational States ◽  
Γ Ray ◽  
Deuteron Stripping ◽  
Experimental Values

A description of the experimental results obtained for Mg25 and Al25 is given based upon the assumption that the excited nuclear states are rotational states. In Mg25 and Al25 members of four rotational bands can be identified. The band based on the ground state can be assigned K = 5/2 whilst the three excited-state bands, two positive parity and one negative parity, can be assigned K = 1/2. The dipole γ-ray transitions between the K = 1/2 bands and the ground state K = 5/2 band are forbidden on the rotational model and it is a salient feature of the γ-ray cascading in Mg25 and Al25 that the ground-state transitions are always amongst the weakest transitions from excited states assigned to K = 1/2 bands. Besides giving a quantitative account of the γ-ray decay of the excited states the rotational model also predicts the number and type of the bands observed. The experimental values of the Mg24(d, p)Mg25 deuteron stripping reduced widths can also be approximately predicted by the model.

The ground state and low-lying excited states of CCCN radical and its ions: a CASSCF/CASPT2 study

2016 ◽  
Vol 94 (9) ◽  
pp. 803-807
Author(s):  
Angyang Yu
Keyword(s):  
Excited States ◽  
Ground State ◽  
Linear Structure ◽  
Electronic Configuration ◽  
Geometric Optimization ◽  
Oscillator Strengths ◽  
Basis Set ◽  
Excitation Energies ◽  
Complete Active Space ◽  
Vertical Excitation

The ground state and low-lying excited states of the CCCN radical and its ions have been investigated systematically using the complete active space self-consistent field (CASSCF) and multi-configuration second-order perturbation theory (CASPT2) methods in conjunction with the ANO-RCC-TZP basis set. The calculated results show that the state 12Σ+ has the lowest CASPT2 energy among the electronic states. By means of the geometric optimization of this radical, it could be found that the molecule exhibits linear structure, with the bond lengths R1 = 1.214 Å, R2 = 1.363 Å, R3 = 1.162 Å, which are very close to the experimental values. The calculated vertical excitation energies and the corresponding oscillator strengths show that there are three relatively strong peaks at energies 0.63, 4.04, and 5.49 eV, which correspond to the transitions 12Σ+ → 12Π, 12Σ+ → 22Π, and 12Σ+ → 22Σ+, respectively. Additionally, the electronic configuration and the harmonic vibration frequencies of each state are also investigated.

scholarly journals Electron Scattering from the Ground and Excited States of Barium

1999 ◽  
Vol 52 (3) ◽  
pp. 603
Author(s):  
Dmitry V. Fursa
Keyword(s):  
Excited States ◽  
Electron Scattering ◽  
Cross Sections ◽  
Differential Cross ◽  
Ground State ◽  
Differential Cross Sections ◽  
Close Coupling ◽  
Angular Correlations ◽  
Electron Photon ◽  
Good Agreement

We have used the nonrelativistic convergent close-coupling (CCC) method to investigate electron scattering from the ground (6s2)1S state and excited (6s6p)1 Po1 and (6s5d)1,3De2 states of barium. For the scattering from the barium ground state, we have found very good agreement with measurements of (6s6p)1 Po1 apparent cross sections at all energies. Similarly, good agreement is found for differential cross sections for elastic scattering and (6s6p)1 Po and (6s5d)1 De2 excitations and with the (6s6p)1 Po1 state electron{photon angular correlations. For the scattering from excited states of barium we have found good agreement with elastic (6s6p)1 Po1 scattering and the (6s5d)1De2 → (6s6p)1 Po1 transition for both differential cross sections and electron–photon angular correlations.

MR-CISD and MR-AQCC Calculation of Excited States of Malonaldehyde: Geometry Optimizations Using Analytical Energy Gradient Methods and a Systematic Investigation of Reference Configuration Sets

2003 ◽  
Vol 68 (3) ◽  
pp. 447-462 ◽  
Author(s):  
Silmar A. do Monte ◽  
Michal Dallos ◽  
Thomas Müller ◽  
Hans Lischka
Keyword(s):  
Excited States ◽  
Ground State ◽  
Transition Energy ◽  
Gradient Methods ◽  
Systematic Investigation ◽  
Oscillator Strengths ◽  
Excitation Energies ◽  
Band Maximum ◽  
Vertical Excitation ◽  
Energy Gradient

Extended MR-CISD and MR-AQCC calculations have been performed on the ground state and the first two excited states of malonaldehyde. Full geometry optimizations have been carried for Cs and C2v structures both at MR-CISD and MR-AQCC levels. Vertical and minimum-to-minimum excitation energies and oscillator strengths have been computed. Systematic studies have been undertaken concerning several types of reference spaces. Agreement with the experimental 0-0 transition energy to the S1 state (expt. 3.50 eV, calc. 3.56 eV) and for the vertical excitation to S2 (expt. band maximum 4.71 eV, best estimate 4.86 eV) is very good. In agreement with the CASSCF/CASPT2 results by Sobolewski and Domcke (J. Phys. Chem. A 1999, 103, 4494), we find that the hydrogen bond in malonaldehyde is weakened by excitation to the S1 state. The barrier for proton transfer in the S1 state is increased in comparison with the ground state.

Shell model description of the 0+ and 0− excited states in sd shell nuclei

2018 ◽  
Vol 96 (7) ◽  
pp. 774-778 ◽  
Author(s):  
M. Bouhelal ◽  
N. Saidane ◽  
S. Belaid ◽  
F. Haas
Keyword(s):  
Shell Model ◽  
Excited States ◽  
Ground State ◽  
Model Description ◽  
Excitation Energies ◽  
Model Calculations ◽  
The Future

The purpose of this work is to describe, in light of shell model calculations using the PSDPF interaction, the particular states with J = 0 in sd shell nuclei. These states are difficult to observe. It is well known that the ground state in even–even nuclei has Jπ = 0+ and therefore we are interested in describing their first excited [Formula: see text] states. We have also studied the first and second excited 0− states in all sd nuclei. The experimental and theoretical excitation energies of these states were confronted. This study allowed us to make predictions of the existence of [Formula: see text] and (or) [Formula: see text] states in nuclei, which do not possess these states, or to have an idea of their excitation energies for possible experiments in the future.

Study of levels in 24Mg

1968 ◽  
Vol 46 (12) ◽  
pp. 1381-1401 ◽  
Author(s):  
R. W. Ollerhead ◽  
J. A. Kuehner ◽  
R. J. A. Levesque ◽  
E. W. Blackmore
Keyword(s):  
Angular Correlation ◽  
Beta Decay ◽  
Rotational Band ◽  
Ground State ◽  
Present Experiment ◽  
Gamma Ray ◽  
Axially Symmetric ◽  
Excitation Energies ◽  
Rotational Model ◽  
Rotational Bands

Nineteen levels in 24Mg have been studied utilizing the reaction 12C(16O, αγ)24Mg. Angular correlation measurements have established the spins and parities of levels at excitation energies of 7.35, 7.56, 7.62, 8.44, 8.65, 9.00, 9.15, and 10.1 MeV as 2+, 1−, 3−, 1−, 2+, 2+, 1−, and 0+ respectively. Levels at 8.12 and 13.18 MeV have been identified as the 6+ and 8+ members of the K = 0 ground-state rotational band; levels at 7.81 and 9.52 MeV have been identified as the 5+ and 6+ members of the K = 2 rotational band based on the 2+ level at 4.23 MeV. The existence of doublets has been established at excitation energies of 8.44 and 9.52 MeV; in each case, one member of the doublet is populated in the beta decay of 24Al, and the present experiment indicates that these two levels have spin and parity 4+. Assignments are also suggested for levels at 7.75 MeV (1+) and 8.36 MeV (2+). Gamma-ray spectra have been obtained for levels at 8.86, 9.28, and 9.46 MeV. The properties of levels assigned to rotational bands are compared to the predictions of the rotational model for an axially symmetric nucleus.

The structure and vertical excitation energies of the chlorothioformyl radical, ClCS: implications for the photofragmentation of thiophosgene

1993 ◽  
Vol 71 (1) ◽  
pp. 112-117 ◽  
Author(s):  
M. Hachey ◽  
F. Grein ◽  
R. P. Steer
Keyword(s):  
Energy Level ◽  
Ab Initio ◽  
Excited States ◽  
Ground State ◽  
Excited Electronic State ◽  
Excitation Energies ◽  
Electronically Excited States ◽  
Vertical Excitation ◽  
Electronically Excited ◽  
Vertical Excitation Energies

Ab initio CI studies have been performed to determine the geometry of the ground and first electronically excited states of the chlorothioformyl radical, ClCS, and the vertical excitation energies of its ten lowest doublet states and two lowest quartet states. The results are used to construct a more complete energy level correlation diagram for the photofragmentation of Cl2CS. The lowest excited electronic state of ClCS lies only 0.79 eV (adiabatic) above the ground state. Its discovery indicates that the results of previous photofragmentation experiments may need to be reinterpreted.

SYSTEMATIC STUDY OF THE MANY-PARTICLE AND MANY-HOLE STATES IN AND AROUND THE ISLAND OF INVERSION

2011 ◽  
Vol 20 (04) ◽  
pp. 893-896 ◽  
Author(s):  
MASAAKI KIMURA
Keyword(s):  
Molecular Dynamics ◽  
Excitation Energy ◽  
Excited States ◽  
Systematic Study ◽  
Ground State ◽  
Negative Parity ◽  
Parity Assignment ◽  
Island Of Inversion ◽  
The Many

Deformation and many particle and many hole configurations in the island of inversion are investigated with Antisymmetrized Molecular Dynamics (AMD). The result suggests the coexistence of many particle and many hole configurations with different deformation at small excitation energy. In the case of 33 Mg , we suggest the negative-parity assignment for the ground state. Other particle hole configurations are predicted as the excited states.

STUDY OF "CONDENSATE" STATES IN 12C AND 16O BY INELASTIC SCATTERING

2008 ◽  
Vol 17 (10) ◽  
pp. 2118-2123 ◽  
Author(s):  
A. S. DEMYANOVA ◽  
A. A. OGLOBLIN ◽  
S. A. GONCHAROV ◽  
T. L. BELYAEVA
Keyword(s):  
Inelastic Scattering ◽  
Excited States ◽  
Ground State ◽  
Transfer Reaction ◽  
Alpha Particles ◽  
Angular Distributions ◽  
Hoyle State

Study of some properties of the lowest states of 12 C , including the second 0+, 7.65 MeV (Hoyle) state by inelastic scattering of alpha-particles and 3 He were carried out. Two independent methods of measuring the radii of the short-lived excited states based on the analysis of diffraction and rainbow patterns of the angular distributions were proposed. Both methods showed that Hoyle state radius is by factor ~ 1.2 – 1.3 larger than that of the ground state. 8 Be transfer reaction was identified. The probability of L = 0 configuration in Hoyle state occurred to be 3 times larger than in the ground state indicating to the significant presence of condensate configuration in the former one.

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