scholarly journals Excitation of the Ground-State Rotational Band in 28Si by Inelastic Scattering of 25.25 MeV Polarized Protons

1973 ◽  
Vol 51 (12) ◽  
pp. 1293-1299 ◽  
Author(s):  
R. de Swiniarski ◽  
H. E. Conzett ◽  
C. R. Lamontagne ◽  
B. Frois ◽  
R. J. Slobodrian
Keyword(s):  
Inelastic Scattering ◽  
Cross Sections ◽  
Ground State ◽  
Optical Potential ◽  
Great Sensitivity ◽  
Angular Distributions ◽  
Rotational Model ◽  
Coupled Channels ◽  
Polarized Protons ◽  
State Band

Angular distributions of the analyzing power and cross sections have been measured for the elastic and inelastic scattering of 25.25 MeV protons exciting the K = 0+ ground-state band in 28Si. Good agreement with experiment is obtained in the coupled-channels formalism on the basis of the rotational model with a quadrupole deformation β2 = −0.40 (oblate) and a hexadecapole deformation β4 = +0.15. The calculations show the great sensitivity of the experimental results to both the magnitude and sign of the quadrupole and hexadecapole deformations. Equivalent fits of the data were obtained either by keeping the deformation length of the various deformed terms of the optical potential constant (δ0 = β0R0 = βIRI = βLSRLS) or by increasing the deformation of the spin–orbit optical potential relative to the central potential by a factor of 1.5 (βLS = 1.5βcent).

Elastic and inelastic scattering of α-particles by 20Ne nuclei at energy of 48.8MeV

2018 ◽  
Vol 27 (05) ◽  
pp. 1850042
Author(s):  
N. Burtebayev ◽  
A. Duisebayev ◽  
B. A. Duisebayev ◽  
T. Zholdybayev ◽  
Marzhan Nassurlla ◽  
...  
Keyword(s):  
Inelastic Scattering ◽  
Electron Scattering ◽  
Cross Sections ◽  
Coulomb Excitation ◽  
Rotational Model ◽  
Elastic And Inelastic Scattering ◽  
State Band ◽  
Coupled Channel ◽  
Good Agreement ◽  
Α Particles

Differential cross-sections for the elastic and inelastic scattering of [Formula: see text]-particles had been measured at the energy of 48.8[Formula: see text]MeV with excitation of low-lying states of the [Formula: see text] nucleus. The data for transitions to the ground [Formula: see text] and excited [Formula: see text], [Formula: see text] states relating to the ground state band were analyzed in the framework of the optical model and the coupled-channel method based on the rotational model. It is shown that the analysis is sensitive not only to the magnitude, but also to the sign of the quadrupole and hexadecapole deformations. The extracted values of the parameters [Formula: see text] and [Formula: see text] are in good agreement with the results of other experiments on the scattering of protons, [Formula: see text] and [Formula: see text]-particles and correspond to the data known from the electron scattering and Coulomb excitation.

Elastic and inelastic scattering of 40 MeV polarized protons from 90Zr and 92Zr

1979 ◽  
Vol 57 (4) ◽  
pp. 540-549 ◽  
Author(s):  
R. de Swiniarski ◽  
Dinh-Lien Pham ◽  
G. Bagieu ◽  
H. V. Geramb
Keyword(s):  
Inelastic Scattering ◽  
Cross Sections ◽  
Imaginary Component ◽  
Spin Orbit ◽  
Model Calculations ◽  
Analyzing Powers ◽  
Elastic And Inelastic Scattering ◽  
Polarized Protons ◽  
The Cross ◽  
Good Agreement

Analyzing powers and cross sections have been measured for elastic and inelastic scattering of 40 MeV polarized protons from 90Zr and 92Zr. The analysis has been carried out in the DWBA within the framework of the macroscopic and microscopic models. Furthermore, the coupled-channels calculations using the vibrational model and the full Thomas form for the spin–orbit potential give a very good description for both the cross sections and the analyzing powers of the iow-lying2+, 3−, 5−, and 4+ states in 92Zr and the 2+ and 3− in 90Zr. The cross section and analyzing power for the first 2+ state in these nuclei were compared with previous results at 30 and 20.3 MeV, and from this comparison a certain energy dependence of the relative strength of the spin–orbit deformation to the central deformation could be observed. Microscopic model calculations with tensor and spin–orbit components included in the projectile–target real interaction and with an exact treatment of knock-on' exchange have been performed for the 2+ states in these nuclei. An attempt has also been made in order to include the imaginary component in the N–N interaction. For these calculations, rather good agreement was obtained especially for the 2+ state in 92Zr but poor agreement for 90Zr. Finally, valence plus core polarization calculations have also been done and showed a very good agreement between theory and experiment for those 2+ transitions.

THE SCATTERING OF PROTONS ON 7Li, 9Be, AND 12C AT 100 MEV

1966 ◽  
Vol 44 (12) ◽  
pp. 2961-2971 ◽  
Author(s):  
S. K. Mark ◽  
P. M. Portner ◽  
R. B. Moore
Keyword(s):  
Angular Distribution ◽  
Inelastic Scattering ◽  
Cross Sections ◽  
Differential Cross ◽  
Target Nucleus ◽  
Energy Region ◽  
Angular Distributions ◽  
Angular Range ◽  
Existing Data ◽  
Octupole Excitation

Elastic and inelastic scattering of protons on 7Li, 9Be, and 12C have been studied, using the 100-MeV proton beam from the McGill synchrocyclotron. Differential cross sections for the various groups of scattered protons were measured over an angular range of 5° to 90° (lab). For proton groups resulting from a quadrupole excitation in the target nucleus, the angular distribution was found to increase at scattering angles less than 10°. Angular distributions corresponding to an octupole excitation were observed to decrease at small angles. The results have been compared with existing data in this energy region.

QUASICLASSICAL TRAJECTORY STUDY OF PRODUCT POLARIZATIONS IN THE H(2S) + NH → N(4S) + H2 REACTION

2012 ◽  
Vol 11 (06) ◽  
pp. 1297-1310 ◽  
Author(s):  
LIN LI ◽  
SHUNLE DONG
Keyword(s):  
Angular Momentum ◽  
Cross Sections ◽  
Differential Cross ◽  
Ground State ◽  
Calculation Method ◽  
Collision Energy ◽  
Potential Surface ◽  
Angular Distributions ◽  
Title Reaction ◽  
Energy Dependent

Based on the DMBE potential surface of the 4 A ″ ground-state, the product rotational polarizations in the title reaction are studied by using quasiclassical trajectory (QCT) calculation method. Three angular distributions of P(θr), P(Φr), P(θr, Φr) and the four polarization-dependent differential cross sections (PDDCSs) were calculated for the collision energy range of 1–20 kcal/mol. The results revealed that the product is backward-scattering and the product rotational angular momentum j′ is aligned and oriented. With the increment of collision energy, the degree of the product alignment and orientation is enhanced, showing the collision energy-dependent behaviors of the product polarizations.

scholarly journals Simplified DWBA for Heavy Ion Induced Transfer at High Energies

1979 ◽  
Vol 32 (3) ◽  
pp. 173 ◽  
Author(s):  
LR Dodd
Keyword(s):  
Excited States ◽  
Cross Sections ◽  
Ground State ◽  
Optical Model ◽  
Heavy Ion ◽  
Transfer Reactions ◽  
Angular Distributions ◽  
High Energies ◽  
Scattering States ◽  
Exact Calculations

The treatment of the distorted wave Born approximation (DWBA) for transfer reactions at high energies between complex nuclei due to Braun-Munzinger and Harney (1974) is simplified by introducing eikonal-like representations for the elastic scattering states. Simple expressions for the differential cross sections are derived. The model includes recoil approximately and takes into account the strong absorption of the nuclear cores. Reasonable values for the parameters of the model wavefunctions are determined by comparison with the usual optical model wavefunctions. Angular distributions calculated for the model are compared with the results of exact finite-range DWBA calculations and experimental data for transitions to the ground state and excited states of 13C in the reaction 12C(14N,13N)13C at several energies. The model reproduces the general features of the exact calculations, giving reasonable fits for the transitions to the ground state and the 1ds/2 (3�85 MeV) state. The transition to the 2S1/2 (3 �09 MeV) state appears to be anomalous as in the case of the full DWBA theory.

The (K−,π−) and (π+, K+) Reactions and Λ-Hypernuclear Polarization

1994 ◽  
Vol 117 ◽  
pp. 17-53 ◽  
Author(s):  
K. Itonaga ◽  
T. Motoba ◽  
M. Sotona
Keyword(s):  
Experimental Data ◽  
Excited States ◽  
Cross Sections ◽  
Ground State ◽  
Weak Decay ◽  
Angular Distributions ◽  
Theoretical Studies ◽  
Excitation Functions ◽  
Unnatural Parity ◽  
Natural Parity

The theoretical studies of (K−, π−) and (π+, K+) reactions on p-shell targets are presented in the DWIA framework with use of the elementary spin-nonflip and spin-flip amplitudes. Calculations can explain the available experimental data of excitation functions and angular distributions of the (K−, π−) reactions at pK−=800 MeV/c and the (π+, K+) reactions at pπ+ = 1.04 GeV/c. Characteristic and distinguished features of the excitation functions and cross sections are exhibited. Especially it is demonstrated that the (K−, π−) reactions at pK−=1.1 GeV/c and 1.5 GeV/c can excite the unnatural parity states with comparable strength to the natural parity ones. Further interesting is that the (π+, K+) and (K−, π−) reactions with ∼1 GeV/c incident beams can be shown to produce very large polarizations of the produced hypernuclear states. Taking the subsequent deexcitation processes of the excited states into account, we have evaluated the hypernuclear polarization and Λ-spin polarization of the ground state and/or the ground-doublet states at the hypernuclear weak-decay stage, which would play a role in the hypernuclear coincidence experiment.

scholarly journals Interaction of real and virtual NN̅ pairs in J/ψ decays

2018 ◽  
Vol 181 ◽  
pp. 01020
Author(s):  
Alexander Milstein ◽  
Sergey Salnikov
Keyword(s):  
Experimental Data ◽  
Mass Spectrum ◽  
Invariant Mass ◽  
Cross Sections ◽  
Energy Region ◽  
Mass Spectra ◽  
Optical Potential ◽  
Invariant Mass Spectrum ◽  
Decay Rates ◽  
Angular Distributions

The differential decay rates of the processes J/ψ→pp̅π0, J/ψ→pp̅η, J/ψ→pp̅ω, J/ψ→pp̅ρ, and J/ψ→pp̅γ close to the pp̅ threshold are calculated with the help of the NN̅ optical potential. We use the potential which has been suggested to fit the cross sections of NN̅ scattering together with all other NN̅ experimental data available. The pp̅ nvariant mass spectra of J/ψ decays are in agreement with the available experimental data. The anisotropy of the angular distributions of the decays J/ψ→pp̅π0(η), which appears due to the tensor forces in the NN̅ interaction, is predicted close to the pp̅ threshold. This anisotropy is large enough to be investigated experimentally. Such measurements would allow one to check the accuracy of the model of NN̅ interaction, is predicted close to the pp̅ threshold. This anisotropy is large enough to be investigated experimentally. Such measurements would allow one to check the accuracy of the model of NN̅ interaction. Using our potential and the Green’s function approach we also describe the peak in the η′ π+ π- invariant mass spectrum in the decay J/ψ → γ η′ π+ π- in the energy region near the NN̅ threshold.

Scattering of α-particles and 3He on 16O nuclei and its excitation mechanism at energies near 50MeV

2017 ◽  
Vol 26 (04) ◽  
pp. 1750018 ◽  
Author(s):  
N. Burtebayev ◽  
A. Duysebayev ◽  
B. A. Duysebayev ◽  
J. Burtebayeva ◽  
M. Nassurlla ◽  
...  
Keyword(s):  
Inelastic Scattering ◽  
Good Description ◽  
Center Of Mass ◽  
Angular Distributions ◽  
Octupole Deformation ◽  
Coupled Channels ◽  
Cluster Transfer ◽  
Microscopic Models ◽  
Nuclear Rainbow ◽  
Α Particles

Elastic and inelastic scattering of [Formula: see text]-particles at 48.1[Formula: see text]MeV and 3He at 60[Formula: see text]MeV on [Formula: see text]O nuclei has been measured with excitation of states at 6.05 (0[Formula: see text])–6.13 (3[Formula: see text])[Formula: see text]MeV, 6.92 (2[Formula: see text])–7.12 (1[Formula: see text])[Formula: see text]MeV and 8.87 (2[Formula: see text])[Formula: see text]MeV. The center-of-mass beam momenta are the same for these two strongly absorbed particles. Analysis of angular distributions was performed in the frameworks of the optical model, the coupled channels method and the Distorted Wave Born Approximation (DWBA). A good description of experimental data was obtained over the full angular range without taking into account the spin-orbit interaction and the cluster transfer mechanism with real potentials that have volume integrals of about 400[Formula: see text]MeV fm3. Collective and microscopic models were used in the analysis of the inelastic scattering. The values of the octupole deformation lengths were extracted. It is shown that nuclear rainbow effects appear not only in the elastic, but also in the inelastic scattering with excitation of the 3[Formula: see text] state of [Formula: see text]O.

THE ANGULAR DISTRIBUTION AND YIELD OF THE REACTION F19(p, α0)O16

1957 ◽  
Vol 35 (2) ◽  
pp. 155-167 ◽  
Author(s):  
R. L. Clarke ◽  
E. B. Paul
Keyword(s):  
Angular Distribution ◽  
Least Squares ◽  
Cross Sections ◽  
Legendre Polynomial ◽  
Ground State ◽  
Energy Region ◽  
Alpha Particles ◽  
Angular Distributions ◽  
Method Of Least Squares ◽  
Channel Spin

The yield of the ground state alpha particles from the F19(p, α0)O16 reaction has been studied from an energy of 1.3 Mev. to 2.7 Mev. The observed angular distributions were analyzed in terms of a Legendre polynomial expansion by the method of least squares. Six resonances were found in the energy region studied, at bombarding energies of 1.358 Mev., 1.709 Mev., 1.853 Mev., 2.11 Mev., 2.31 Mev., and 2.58 Mev. The widths and peak cross sections of these resonances are respectively: (54 ± 10 kev., 46 ± 5 mb.), (140 ± 5 kev., 55 ± 6 mb.), (132 ± 5 kev., 77 ± 8 mb.), (75 ± 25 kev., 10 ± 2 mb.), (80 ± 25 kev., 32 ± 5 mb.), and (300 ± 25 kev., 51 ± 10 mb.). Their spins, parities, channel spin mixtures, and partial widths are discussed.

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