Mixed Positive Parity States in 165Er

1975 ◽  
Vol 53 (9) ◽  
pp. 922-929 ◽  
Author(s):  
W. R. Stott ◽  
J. C. Waddington ◽  
D. G. Burke ◽  
G. Løvhøiden
Keyword(s):  
Excitation Energy ◽  
Model Calculation ◽  
Positive Parity ◽  
Angular Distributions ◽  
Excitation Energies ◽  
Nilsson Model ◽  
Population Processes

Positive parity states in 165Er have been studied using the 167Er(p,t)165Er reaction. Two 7/2+ states at excitation energies of 63 and 465 keV were populated via l = 0 transitions. Because of the lack of a pronounced minimum in the l = 0 angular distributions, some l ≠ 0 strength may contribute to the population processes. Eight l ≠ 0 transitions were seen below 1 MeV excitation energy. A description of the observed positive parity levels has been attempted in the context of a Coriolis coupled Nilsson model calculation.

A study of levels in 155Dy using the (d,t) and (3He,α) reactions

1976 ◽  
Vol 54 (12) ◽  
pp. 1258-1273 ◽  
Author(s):  
O. Straume ◽  
D. G. Burke ◽  
T. F. Thorsteinsen
Keyword(s):  
Nuclear Structure ◽  
Cross Sections ◽  
Negative Parity ◽  
Positive Parity ◽  
Angular Distributions ◽  
Coriolis Coupling ◽  
Reaction Products ◽  
Nilsson Model ◽  
Photographic Emulsions ◽  
Peak Widths

The (d,t) and (3He, α) reactions on a target of 156Dy have been used to study the nuclear structure of 155Dy. Beams of 15 MeV deuterons and 24 MeV 3He were obtained from the McMaster University FN tandem Van de Graaff accelerator. The reaction products were analyzed with an Enge-type magnetic spectrograph and detected in photographic emulsions. The (d,t) reaction was studied at 15 angles with typical peak widths (FWHM) of ~ 6 keV and (3He,α) exposures were made at 5 angles with peak widths of ~ 18 keV. The (d,t) angular distributions and ratios of the (3He,α) and (d,t) cross sections were used to determine l values for a number of transitions. It is found that the positive parity states can be described in terms of the Nilsson model when Coriolis coupling is included while for the negative parity states only the gross features are well-described this way.

The 23Na(α,γ)27Al reaction. A survey of the reaction and some properties of the 27Al nucleus

1969 ◽  
Vol 47 (15) ◽  
pp. 1545-1555 ◽  
Author(s):  
H. Röpke ◽  
N. Anyas-Weiss
Keyword(s):  
Excitation Energy ◽  
Excited States ◽  
Bound States ◽  
Branching Ratios ◽  
Angular Distributions ◽  
Particle Capture ◽  
Excitation Energies ◽  
Decay Modes ◽  
Γ Ray ◽  
27Al Reaction

The 23Na(α,γ) reaction has been studied in the region Eα = 2–3 MeV. The γ-ray spectra from a total of 16 resonances have been surveyed using a 40 cm3 Ge(Li) detector. Excitation energies, γ-ray decay modes, branching ratios, and γ-ray yields of these resonances are given. Below Eα = 2.7 MeV, all resonances have [Formula: see text] and the α-particle capture proceeds with [Formula: see text]. The resonances at Eα = 2.696 and 2.797 MeV have strong branches to the Jπ = 11/2+ state in 27Al at 4.509 MeV excitation energy. A measurement of γ-ray angular distributions at these resonances yields Jπ(2.969 res.) = 9/2+, 11/2 and Jπ(2.797 res.) = 9/2+ for the resonances, and Jπ(5.671) = 9/2+, 7/2 and Jπ(4.580) = 9/2+, 7/2 for bound states in 27Al. Investigation of this latter level at the Ep = 2.114 MeV resonance in the 26Mg(p,γ)27Al reaction restricts the spin to 7/2. New excited states in 27Al were found at Ex = 5.504, 5.671, and 7.815 MeV. A state at Ex = 5.499 MeV was confirmed.

A Study of Levels in 153Gd Using the (d,t) and (3He,α) Reactions

1973 ◽  
Vol 51 (22) ◽  
pp. 2354-2368 ◽  
Author(s):  
G. Løvhøiden ◽  
D. G. Burke
Keyword(s):  
Cross Sections ◽  
Negative Parity ◽  
Positive Parity ◽  
Angular Distributions ◽  
Reaction Products ◽  
Ground State Band ◽  
Intensity Pattern ◽  
Nilsson Model ◽  
State Band ◽  
Photographic Emulsions

Triton spectra from the 154Gd(d,t)153Gd reaction have been measured at 15 angles using a beam of 15 MeV deuterons. The 154Gd(3He,α)153Gd reaction was studied at 4 angles with a 24 MeV 3He beam. The reaction products were analyzed with an Enge-type magnetic spectrograph and detected with photographic emulsions. The (d,t) angular distributions and ratios of the (3He,α) and (d,t) cross sections were used to determine l values for a number of transitions. Members of the strongly perturbed band consisting of a mixture of Nilsson states from the i13/2 shell have been populated. An attempt has been made to describe some of the positive parity states in terms of the Nilsson model with Coriolis and ΔN = 2 mixings included. As spin assignments are now available for a large number of positive parity levels, it is possible to see a better developed pattern for this mixing than was presented previously. Although the observed intensity pattern for the 3/2−[521] ground-state band agrees with expectations, the remaining negative parity states cannot be easily explained in terms of the basic Nilsson model.

Modification of HAM/3 excitation energies for ΠΠ* transitions of linear molecules

1980 ◽  
Vol 58 (16) ◽  
pp. 1687-1690 ◽  
Author(s):  
Delano P. Chong
Keyword(s):  
Excitation Energy ◽  
Explicit Expression ◽  
Excited States ◽  
Configuration Interaction ◽  
Excitation Energies ◽  
Carbon Suboxide ◽  
Numerical Examples ◽  
Energy Correction ◽  
Linear Molecules ◽  
Configuration Interaction Calculations

The excitation energies calculated by the HAM/3 procedure for ΠΠ* transitions in linear molecules can be internally inconsistent by as much as ± 0.6 eV. In the recent study by Åsbrink etal., the problem was avoided by adopting Recknagel's expressions and requiring the proper average ΠΠ* excitation energy. In this paper, we trace the small inconsistency back to its origin in HAM/3 theory and derive the analytical expression for the energy correction as well as Recknagel's formulas. Numerical examples studied include all seven linear molecules investigated by Åsbrink etal. The explicit expression for the correction enables us to perform meaningful configuration-interaction calculations on the excited states, as illustrated by the carbon suboxide molecule.

scholarly journals Predicting the UV–vis spectra of oxazine dyes

2011 ◽  
Vol 7 ◽  
pp. 432-441 ◽  
Author(s):  
Scott Fleming ◽  
Andrew Mills ◽  
Tell Tuttle
Keyword(s):  
Excitation Energy ◽  
Density Functional ◽  
Polarizable Continuum Model ◽  
Implicit Solvent ◽  
Continuum Approach ◽  
Excitation Energies ◽  
Functional Theory ◽  
Partial Charges ◽  
Td Dft ◽  
Polarizable Continuum

In the current work we have investigated the ability of time-dependent density functional theory (TD-DFT) to predict the absorption spectra of a series of oxazine dyes and the effect of solvent on the accuracy of these predictions. Based on the results of this study, it is clear that for the series of oxazine dyes an accurate prediction of the excitation energy requires the inclusion of solvent. Implicit solvent included via a polarizable continuum approach was found to be sufficient in reproducing the excitation energies accurately in the majority of cases. Moreover, we found that the SMD solvent model, which is dependent on the full electron density of the solute without partitioning into partial charges, gave more reliable results for our systems relative to the conductor-like polarizable continuum model (CPCM), as implemented in Gaussian 09. In all cases the inclusion of solvent reduces the error in the predicted excitation energy to <0.3 eV and in the majority of cases to <0.1 eV.

scholarly journals A New Benchmark Set for Excitation Energy of Charge Transfer States: Systematic Investigation of Coupled-Cluster Type Methods

2020 ◽  
Author(s):  
Balázs Kozma ◽  
Attila Tajti ◽  
Baptiste Demoulin ◽  
Róbert Izsák ◽  
Marcel Nooijen ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Excitation Energy ◽  
Systematic Investigation ◽  
Coupled Cluster ◽  
Excitation Energies ◽  
Chemical Methods ◽  
Valence States ◽  
Quantum Chemical Methods ◽  
Material Physics ◽  
Cluster Methods

There are numerous publications on benchmarking quantum chemistry methods for excited states. These studies rarely include Charge Transfer (CT) states although many interesting phenomena in e.g. biochemistry and material physics involve transfer of electron between fragments of the system. Therefore, it is timely to test the accuracy of quantum chemical methods for CT states, as well. In this study we first suggest a set benchmark systems consisting of dimers having low-energy CT states. On this set, the excitation energy has been calculated with coupled cluster methods including triple excitations (CC3, CCSDT-3, CCSD(T)(a)* ), as well as with methods including full or approximate doubles (CCSD, STEOM-CCSD, CC2, ADC(2), EOM-CCSD(2)). The results show that the popular CC2 and ADC(2) methods are much more inaccurate for CT states than for valence states. On the other hand, CCSD seems to have similar systematic overestimation of the excitation energies for both valence and CT states. Concerning triples methods, the new CCSD(T)(a)* method including non-iterative triple excitations preforms very well for all type of states, delivering essentially CCSDT quality results.<br>

SHAPE EVOLUTION OF 96ZR AND 96MО WITH EXCITATION ENERGY INCREASE

2019 ◽  
pp. 37-41
Author(s):  
M.A. Mardyban ◽  
D.A. Sazonov ◽  
E.A. Kolganova ◽  
R.V. Jolos
Keyword(s):  
Potential Energy ◽  
Excitation Energy ◽  
Transition Probabilities ◽  
Collective Excitations ◽  
Nuclear Model ◽  
Shape Evolution ◽  
Energy Increase ◽  
Excitation Energies ◽  
Satisfactory Description

The observed properties of the low-lying collective excitations of 96Zr and 96Mo are investigated in the framework of the collective quadrupole nuclear model with the Bohr Hamiltonian, whose potential energy has two minima – spherical and deformed. Satisfactory description of the excitation energies and E2 transition probabilities is obtained. It is shown that in the case of 96Zr both minima are sufficiently deep. However, in the case of 96Mo a deformed minimum is only outlined.

scholarly journals Nuclear disintegrations produced by cosmic rays

1949 ◽  
Vol 196 (1046) ◽  
pp. 325-343 ◽  
Keyword(s):  
Cosmic Radiation ◽  
High Energy ◽  
Energy Spectra ◽  
Angular Distributions ◽  
Excitation Energies ◽  
Wide Range ◽  
High Energy Tail ◽  
Energy And Angular Distributions ◽  
Photographic Emulsions ◽  
Α Particles

Measurements have been made on the energy and angular distributions of the charged particles from disintegration ‘stars’ produced in the silver and bromine nuclei of photographic emulsions exposed to cosmic radiation. The observations extended over a wide range of excitation energies (100 to 700 MeV). The energy spectra and angular distributions of the protons can be explained in all cases by simple evaporation theory. This energy distribution shows also a high-energy tail consisting of direct knock-on protons and slow mesons. At high excitation energies the α-particles exhibit collimation effects which are probably due to localized ‘boiling’ or a form of fission.

GT± STRENGTH DISTRIBUTION IN 48Sc AND 116In MEASURED BY (p, n) AND (n, p) REACTIONS AT 300 MeV AND THEIR IMPLICATIONS FOR 2ν2β DECAY

2009 ◽  
Vol 18 (10) ◽  
pp. 2119-2123
Author(s):  
HIDE SAKAI ◽  
KENTARO YAKO ◽  
ICHOR COLLABORATION
Keyword(s):  
Matrix Element ◽  
Excitation Energy ◽  
Cross Sections ◽  
Nuclear Matrix ◽  
Differential Cross ◽  
Nuclear Matrix Element ◽  
Strength Distribution ◽  
Angular Distributions ◽  
Decomposition Technique ◽  
Gamow Teller

Angular distributions of the double differential cross sections for the 48 Ca , 116 Cd (p, n) and the 48 Ti , 116 Sn (n, p) reactions were measured at 300 MeV. A multipole decomposition technique was applied to the spectra to extract the Gamow-Teller (GT) transition strengths. In both (n, p) spectra beyond 8 MeV excitation energy extra B( GT +) strengths which are not predicted by either shell model or QRPA calculations. This extra B( GT +) strengths certainly contribute to the nuclear matrix element of the 2ν2β-decay.

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