Nucleon-nucleus velocity-dependent optical model: Revisited

2021 ◽  
Author(s):  
Sajedah Alalmeer ◽  
M I Jaghoub ◽  
Ibrahim Naji Ghabar
Keyword(s):  
Cross Sections ◽  
Mass Range ◽  
Angular Distributions ◽  
Polarization Data ◽  
Fitting Procedure ◽  
Wide Range ◽  
Local Equivalent ◽  
Potential Parameters ◽  
Best Fit ◽  
Good Agreement

Abstract In this work we study nucleon-nucleus elastic scattering using a nonlocal, velocity-dependent optical potential. The potential parameters are determined by fitting elastic angular distributions and polarization data for nucleon scattering off a wide range of nuclei falling in the mass range $12 \leq A \leq 208$ and over the energy range 10 - 60 MeV. Our potential parameters lead to smoothly varying local equivalent potentials and, unlike previous works, the potential depths corresponding to the real volume, imaginary surface, and imaginary volume terms show systematic linear dependences on energy. In addition, for each nuclear target, we determined constant sets of geometric parameters. Including the polarization data in the fitting procedure helped in reducing the large variations in the depths of the spin-orbit term. Our best-fit angular distributions and polarization data are in very good agreement with measured data, and are either as good as the cross sections obtained with widely-used systematics or better.

Angular distributions of the 12C(e,p)e′ reaction at Ee = 200 MeV

1981 ◽  
Vol 59 (2) ◽  
pp. 271-274 ◽  
Author(s):  
G. J. Lolos ◽  
S. Hontzeas ◽  
R. M. Sealock
Keyword(s):  
Electron Energy ◽  
Cross Sections ◽  
Differential Cross ◽  
Proton Energy ◽  
Incident Electron ◽  
Incident Electron Energy ◽  
Angular Distributions ◽  
Differential Cross Sections ◽  
Good Agreement

Double differential cross sections at six angles ranging from 45° to 143° have been measured for the 12C(e,p)e′ reaction. The proton energy ranged from 15.6 to 17.2 MeV at an incident electron energy of 200 MeV. At the backward angles our results are in good agreement with data reported by Vysotskaya and Afanas'ev but for forward angles the results are lower.

Streuung von Ionen I. Regenbogeneffekt bei der elastischen Streuung von Protonen an Argon

1971 ◽  
Vol 26 (7) ◽  
pp. 1112-1121
Author(s):  
H.-U. Mittmann ◽  
H.-P. Weise ◽  
A. Ding ◽  
A. Henglein
Keyword(s):  
Fine Structure ◽  
Cross Sections ◽  
Differential Cross ◽  
Scattering Data ◽  
Equilibrium Distance ◽  
Jones Potential ◽  
Lennard Jones ◽  
Fitting Procedure ◽  
Potential Depth ◽  
Good Agreement

A crossed beam apparatus for scattering experiments with ions on atoms or molecules is described. The results for the elastic scattering of H+ on Ar are reported. Both the structure of the secondary rainbows and the superimposed fine structure were resolved. In order to fit the experimental curves, differential cross sections were calculated in WKB approximation using the following reduced potentials: n, m, g1, g2 , g3 , L, G1 and G2 are form parameters for adjusting the width of the potential well. The fitting procedure and the influence of the chosen potentials on the resulting potential depth E and the equilibrium distance rm are described. Further, the information which can generally be obtained from the observed rainbows and the superimposed fine structure are discussed. No combination of n, m, rm and ε yielded a differential cross section in agreement with the experiments, if the Lennard-Jones potential ULJ or the modifications of Mason and Vanderslice or Schlier and coworkers are used, but excellent agreement can be obtained with the above expressions for U1 and U2 using suitable parameters. For the system H+-Ar we obtain ε = (4.04+0.1) eV, rm = (1.31±0.07) Å. These values are in good agreement with recent ab-initio calculations of Roach and Kuntz. They are considerably different from those obtained by Champion et al. 8, who did not observe the fine structure and used a too narrow potential in the evaluation of the scattering data.

Applicability of the systematic helium-3 potential for triton-nucleus reactions

2015 ◽  
Vol 24 (01) ◽  
pp. 1550005 ◽  
Author(s):  
Yong-Li Xu ◽  
Hai-Rui Guo ◽  
Yin-Lu Han ◽  
Qing-Biao Shen
Keyword(s):  
Elastic Scattering ◽  
Cross Sections ◽  
Optical Model ◽  
Model Potential ◽  
Reaction Cross ◽  
Angular Distributions ◽  
Optical Model Potential ◽  
Helium 3 ◽  
Reasonable Description ◽  
Potential Parameters

The elastic scattering angular distributions of triton are calculated by the obtained systematic helium-3 global optical model potential parameters and compared with the available experimental data. These results show that the present global optical model potential can give a reasonable description of the elastic scattering of triton. The total reaction cross-sections of triton as a function of energy per nucleon are also further investigated and the reasonable results are presented.

scholarly journals Microscopic analysis of elastic scattering cross sections for different densities of $^{8}$Li nucleus on light, medium and heavy mass targets

2019 ◽  
Vol 65 (4 Jul-Aug) ◽  
pp. 404
Author(s):  
M. Aygun ◽  
And Z. Aygun
Keyword(s):  
Elastic Scattering ◽  
Cross Sections ◽  
Microscopic Analysis ◽  
Angular Distributions ◽  
Weakly Bound ◽  
Density Distributions ◽  
Double Folding ◽  
Scattering Cross Sections ◽  
Light Medium ◽  
Good Agreement

The elastic scattering angular distributions of weakly bound nucleus$^{8}$Li on $^{7}$Li, $^{9}$Be, $^{12}$C, $^{13}$C, $^{14}$N,$^{27}$Al, $^{51}$V, $^{58}$Ni, and $^{208}$Pb are analyzed atvarious incident energies. For this purpose, the real potential isgenerated for nine different density distributions of the $^{8}$Linucleus by using the double folding model within the optical model.The theoretical results are in good agreement with the experimentaldata. In our study, also, new and practical sets of imaginarypotentials for the investigated densities are derived.

scholarly journals Next-to-leading-order study of J/ψ angular distributions in e+e− → J/ψ + ηc, χcJ at $$ \sqrt{s} $$ ≈ 10.6 GeV

2021 ◽  
Vol 2021 (9) ◽  
Author(s):  
Zhan Sun
Keyword(s):  
Cross Sections ◽  
Charm Quark ◽  
Experimental Result ◽  
Angular Distributions ◽  
Matrix Elements ◽  
Leading Order ◽  
Charm Quark Mass ◽  
Qcd Factorization ◽  
Nonrelativistic Qcd ◽  
Good Agreement

Abstract In this paper, we present a detailed next-to-leading-order (NLO) study of J/ψ angular distributions in e+e−→ J/ψ + ηc, χcJ (J = 0, 1, 2) within the nonrelativistic QCD factorization (NRQCD). The numerical NLO expressions for total and differential cross sections, i.e., $$ \frac{d\sigma}{d\cos \theta } $$ dσ d cos θ = A + B cos2θ, are both derived. With the inclusion of the newly-calculated QCD corrections to A and B, the αθ (= B/A) parameters in J/ψ + χc0 and J/ψ + χc1 are moderately enhanced, while the magnitude of αθJ/ψ+χc2 is significantly reduced; regarding the production of J/ψ + ηc, the αθ value remains unchanged. By comparing with experiment, we find the predicted αθJ/ψ+ηc is in good agreement with the Belle measurement; however, αθJ/ψ+χc0 is still totally incompatible with the experimental result, and this discrepancy seems to hardly be cured by proper choices of the charm-quark mass, the renormalization scale, and the NRQCD matrix elements.

The Repulsive Part of the Potential Between Hg Atoms and Light Atomic Projectiles

1972 ◽  
Vol 50 (17) ◽  
pp. 1938-1948 ◽  
Author(s):  
A. van Wijngaarden ◽  
B. Miremadi ◽  
W. E. Baylis
Keyword(s):  
Cross Sections ◽  
Target Chamber ◽  
Angular Distributions ◽  
Interatomic Potentials ◽  
Scattering Parameters ◽  
Thomas Fermi ◽  
Monoenergetic Beam ◽  
Charge States ◽  
Repulsive Part ◽  
Good Agreement

Interatomic potentials are studied by means of a crossed beam apparatus consisting of a target chamber in which a monoenergetic beam of H, He, B, and N ions of energies E < 70 keV interacts with a thermal beam of Hg atoms. Angular distributions for the scattering of all charge states of 1H, 4He, 11B, and 14N are measured in the range of 17° < θL < 60°. All measured cross sections are in good agreement with the theory for scattering in a Thomas–Fermi potential to which Lindhard's theoretical estimates are shown to be quite accurate approximations. A Padé approximant is derived for the Thomas–Fermi potential and is used to calculate tables of Thomas–Fermi scattering parameters.

OBSERVATION OF INTERFERENCE BETWEEN ATOMIC BREMSSTRAHLUNG AND NUCLEAR BREMSSTRAHLUNG

1999 ◽  
Vol 09 (01n02) ◽  
pp. 1-10 ◽  
Author(s):  
K. ISHII ◽  
T. SATOH ◽  
S. MATSUYAMA ◽  
H. YAMAZAKI ◽  
Y. TOKAI ◽  
...  
Keyword(s):  
Cross Sections ◽  
Energy Region ◽  
Production Cross ◽  
Angular Distributions ◽  
X Rays ◽  
Beam Direction ◽  
Aluminum Target ◽  
X Ray ◽  
Wide Range ◽  
Mev Protons

An aluminum target was bombarded with 1.5 MeV protons and continuous x-rays were measured at the angles of 45°, 90° and 135° with respect to the beam direction. By investigating the shape of the x-ray energy spectrum, it was recognized that, the continuous x-rays below 12 keV are atomic bremsstrahlung (AB) and those of above 12 keV are nuclear bremsstrahlung (NB), and AB and NB are mingled in the energy region of around 12 keV The x-ray energy dependence of angular distributions presented well a change from the process of AB to that of NB in the continuous x-ray spectrum. Interference between AB and NB were discussed on the basis of PWBA theory. Continuous x-ray production cross sections were calculated on the basis of PWBA BEA and a semi-classical theory and compared with the experimental results. The theoretical prediction reproduced well the experimental cross sections over the wide range of 6 orders in magnitude and of 2 keV – 35 keV in the energy except for the energy region mingled with AB and NB. The ratio of the theoretical cross sections to the experimental ones showed an interference effect between AB and NB in their mingled region.

Spectroscopic information of 6Li from elastic scattering of deuterons, 3He and 4He by 6Li

2014 ◽  
Vol 23 (08) ◽  
pp. 1450041
Author(s):  
A. Amar
Keyword(s):  
Elastic Scattering ◽  
Cross Sections ◽  
Optical Potential ◽  
Wide Energy Range ◽  
Spectroscopic Information ◽  
Wide Energy ◽  
Double Folding ◽  
Potential Parameters ◽  
Coupled Reaction ◽  
Good Agreement

The elastic scattering of deuterons, 3 He and 4 He on 6 Li at different incident energies have been analyzed in the framework of the optical model (OM) using ECIS88 as well as SPI GENOA codes. The optical potential parameters were extracted in the phenomenological treatment. A good agreement between theoretical and experimental differential cross-sections was obtained in whole angular range. Parameters for real part of potential have been also calculated microscopically with double-folding model for the d, 3 He and 4 He scattering, respectively, using DFPOT code. The elastic transfer mechanism has been studied by coupled reaction channel (CRC) method using FRESCO code. Spectroscopic amplitudes of 6 Li ≡ t + 3 He and 6 Li ≡ α + d configurations have been extracted from d, 3 He and 4 He scattering on 6 Li at wide energy range. A comparison between spectroscopic amplitudes obtained from deuteron and α elastically scattering from 6 Li has been made. The extracted spectroscopic amplitudes of 6 Li ≡ 4 He + d( SF = SA 2) from 6 Li (d, 6 Li )d and 6 Li (α, 6 Li )α are not the same as expected theoretically.

The effect of breakup of 6Li on elastic scattering and fusion with 28Si at near barrier energies

2016 ◽  
Vol 25 (01) ◽  
pp. 1650003 ◽  
Author(s):  
Mandira Sinha ◽  
Subinit Roy ◽  
P. Basu ◽  
H. Majumdar
Keyword(s):  
Elastic Scattering ◽  
Energy Dependence ◽  
Cross Sections ◽  
Model Potential ◽  
Angular Distributions ◽  
The Real ◽  
Optical Model Potential ◽  
Coupled Channel ◽  
Potential Parameters ◽  
Existing Data

Elastic scattering angular distributions for 6Li+[Formula: see text]Si system were measured at [Formula: see text] and analyzed along with the existing data from the previous measurements in the energy range of [Formula: see text]. The measured cross-sections and the existing data, forming a set of angular distributions over a range of E/[Formula: see text], were analyzed using the phenomenological optical model potential (OMP). Three different sets of potential parameters were used. The energy dependence of the real and the imaginary potential strengths were, subsequently, extracted at the radius of sensitivity ([Formula: see text]) for the system. Continuum Discretized Coupled Channel (CDCC) calculation was performed to explore the contribution of projectile break-up (BU) on the observed energy dependence of the effective potential for elastic scattering of 6Li from [Formula: see text]Si. The energy variation of the strength of the real potential with continuum coupling was found to agree with the energy dependence of the same extracted from the (OMP) analysis at energies around the barrier. But the behavior of the imaginary strength appeared to be different. The calculated fusion cross-sections, including the effect of BU, clearly overestimated the measured fusion excitation function data in the below and near barrier energies but compared well with the data at higher energies.

Nuclear structure dependence in analyzing powers?

1980 ◽  
Vol 58 (12) ◽  
pp. 1686-1690 ◽  
Author(s):  
W. R. Falk
Keyword(s):  
Nuclear Structure ◽  
Cross Sections ◽  
Form Factors ◽  
Wave Functions ◽  
Angular Distributions ◽  
Structure Dependence ◽  
Analyzing Powers ◽  
Wide Range ◽  
Configuration Mixing ◽  
The Cross

Calculations of the angular distributions of the cross-sections and analyzing powers in the [Formula: see text] Al reaction have been made using microscopic form factors. A wide range of shapes of the microscopic form factors, simulating different degrees of configuration mixing in the nuclear wave functions, fail to provide angular distributions of the analyzing powers that agree with experiment for the 2.73 and 4.41 MeV, 5/2+ states.

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