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.

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.

ANGULAR DISTRIBUTIONS IN GAMMA–ALPHA REACTIONS IN THE NUCLEI OF NUCLEAR EMULSIONS

1965 ◽  
Vol 43 (6) ◽  
pp. 1015-1019 ◽  
Author(s):  
Jan P. Roalsvig
Keyword(s):  
Angular Distribution ◽  
Excited State ◽  
Ground State ◽  
Intensity Ratio ◽  
Alpha Particles ◽  
Angular Distributions ◽  
Nuclear Emulsions

The angular distribution for alpha particles produced by (γ, α) reactions in the nuclei of nuclear emulsions has been measured. For the reaction 16O(γ, α)12C, in which the 12C nucleus is left in its ground state (J = 0+, T = 0), through an excited state at 12.5 MeV in 16O, the angular distribution is in agreement with a mixture of E1 and E2 interactions, with an E2/E1 intensity ratio of 0.50. For the same reaction, through an excited state at 14.3 MeV in 16O, the angular distribution is best represented by a pure E2 interaction.

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).

Excited states of positronium in positron–hydrogen charge exchange

1978 ◽  
Vol 56 (5) ◽  
pp. 565-570 ◽  
Author(s):  
V. S. Kulhar ◽  
C. S. Shastry
Keyword(s):  
Excited States ◽  
Charge Exchange ◽  
Cross Sections ◽  
Ground State ◽  
Born Approximation ◽  
Energy Region ◽  
Hydrogen Charge ◽  
Positronium Formation ◽  
State Approximation ◽  
Higher Excited States

The two state approximation method for the study of the rearrangement collisions is applied to the process of positronium formation in excited states for positron–hydrogen charge exchange collisions. Differential and integrated cross sections are computed for positronium formation in 2S, 2P, and 3S excited states. The results obtained in the energy region 2 to 10 Ry are compared with positronium formation cross sections in ground state. Total positronium formation cross sections including the contributions of capture into all the higher excited states of positronium are also computed in the first Born approximation and the two state approximation in the energy region considered.

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.

Proton?Capture Gamma Rays from Nitrogen?13

1962 ◽  
Vol 15 (3) ◽  
pp. 443 ◽  
Author(s):  
AW Parker ◽  
GG Shute
Keyword(s):  
Angular Distribution ◽  
Excited State ◽  
Elastic Scattering ◽  
Gamma Rays ◽  
Ground State ◽  
Recent Experiment ◽  
Gamma Ray ◽  
Angular Distributions ◽  
Proton Capture ◽  
Yield Curves

From a recent experiment in this laboratory (Shute et al. 1962) on the elastic scattering of protons from 12C, resonance levels (E13N, J1t) of 13N were obtained at the laboratory bombarding energies (Ep) shown in Table 1. To confirm these results, an investigation of the yield and angular distribution of gamma rays from the reaction 12C(p'YO)13N and 12C(p'Yl)13N was undertaken. Accordingly, the theoretical angular distributions, W(8), for the gamma ray (Yo) to the ground state of 13Na-) and also for the gamma ray (Yl) to the 1st excited state of 13Na+) were evaluated on the assumptions that overlap of levels in 13N is small and lowest order multipoles are involved. As angular distributions are parity insensitive, these were found to be identical for the two gamma rays expected. The simpler of these angular distributions are also shown on the table. The expected angular distributions indicate that 90� is a suitable angle for yield curves.

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