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.

The scattering of neutrons by deuterons at high energies

1951 ◽  
Vol 209 (1098) ◽  
pp. 380-396 ◽  
Keyword(s):  
Charge Exchange ◽  
Cross Sections ◽  
Ground State ◽  
Nuclear Potential ◽  
Angular Distributions ◽  
High Energies ◽  
Exchange Properties

Born’s approximation has been used to calculate total elastic and inelastic cross-sections and angular distributions for the scattering of neutrons by deuterons at incident energies of 100, 200 and 300 MeV. The nuclear potential has been taken to be a mixture of central and non-central interactions of the type √ 12 = I 12 (1 - 1/2 g + 1/2 g σ 1 σ 2 + γS 12 ) V(r) , where S 12 = r -2 3σ 1 . rσ 2 . r-σ 1 . σ 2 . Four types of isotopic factor I 12 , giving exchange properties of the neutral, charge exchange, symmetrical and Serber theories, have been investigated. The effect on the scattering of including the D wave of the ground state of the deuteron has been estimated.

scholarly journals A Comparison of Proximity Potentials in the Analysis of Heavy-Ion Elastic Cross Sections

2018 ◽  
Vol 63 (10) ◽  
pp. 881 ◽  
Author(s):  
M. Aygun
Keyword(s):  
Experimental Data ◽  
Elastic Scattering ◽  
Cross Sections ◽  
Optical Model ◽  
Heavy Ion ◽  
Comprehensive Analysis ◽  
Angular Distributions ◽  
Similarities And Differences ◽  
First Time ◽  
Theoretical Results

To obtain alternative nuclear potentials is very important in explaining the heavy-ion reactions, as well as light-ion ones. For this purpose, a comprehensive analysis of six different proximity potentials ([1, 9–12, 15]) is performed for the first time in the present study. In order to see the availability of the potentials, the elastic-scattering angular distributions of 40Ca by different target nuclei from 32S to 208Pb are calculated within the framework of the optical model. The theoretical results are compared with each other and with experimental data. The similarities and differences of the potentials are discussed, and some alternative potentials are proposed.

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).

Systematic nonlocal optical model potential for nucleons

2015 ◽  
Vol 24 (01) ◽  
pp. 1550006 ◽  
Author(s):  
Yuan Tian ◽  
Dan-Yang Pang ◽  
Zhong-Yu Ma
Keyword(s):  
Cross Sections ◽  
Optical Model ◽  
Model Potential ◽  
Nucl Phys ◽  
Angular Distributions ◽  
Model Calculations ◽  
Analyzing Powers ◽  
Optical Model Potential ◽  
Fitting Procedures ◽  
Scattering Cross Sections

Based on the Perey–Buck nonlocal optical model potential, F. Perey and B. Buck, Nucl. Phys. 32 (1962) 353, we obtain a new set of nonlocal optical model potential (NLOMP) parameters for proton and neutron scattering off nuclei. The experimental angular distributions of nucleon scattering off nuclei ranging from 27 Al to 208 Pb with incident energies around 10 MeV to 30 MeV are adopted in the fitting procedures. This NLOMP is energy independent. The chi-squares χ2 obtained in the fittings are comparable to those from the KD03 phenomenological local optical model potentials (OMP) A. Koning and J. Delaroche, Nucl. Phys. A 713 (2003) 231. Good agreement is found in comparisons between optical model calculations using this NLOMP and KD03 in their reproduction to the experimental angular distributions of elastic scattering cross-sections and analyzing powers.

Multi-interaction of multi-nucleon transfer reactions in the whole-angle region

1996 ◽  
Vol 74 (3-4) ◽  
pp. 150-154 ◽  
Author(s):  
A. A. Farra
Keyword(s):  
Cross Sections ◽  
Exchange Process ◽  
Heavy Ion ◽  
Nucleon Nucleon ◽  
Transfer Reactions ◽  
Ion Transfer ◽  
Exchange Processes ◽  
Nucleon Nucleon Interaction ◽  
Double Folding ◽  
Good Agreement

Heavy-ion transfer reactions are studied using the exact finite-range DWBA (distorted wave Born approximation) calculations. To investigate the differential cross sections in the whole-angle region the reaction mechanism is considered as a coherent sum of direct and exchange processes. Both the double-folding microscopic nucleon–nucleon interaction and phenomenological Woods–Saxon form are used for the real and imaginary distorting potentials in the initial and final channels, respectively. The present calculations are in good agreement with the experimental data in the whole angular range. The inclusion of the exchange process improves the cross section's magnitude explicitly and leads to a better description of the backward oscillations. The values of the extracted normalization coefficients obtained are reasonable.

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.

Sign in / Sign up

Export Citation Format

Share Document