Theoretical Evaluation of Neutron-nucleus Scattering Parameters from Experimental Data in the 6 ≤ A ≤ 60 Mass Region

1998 ◽  
Vol 53 (10-11) ◽  
pp. 855-862 ◽  
Author(s):  
A. Aleksejevs ◽  
S. Barkanova ◽  
J. Tambergs ◽  
T. Krasta ◽  
W. Waschkowski ◽  
...  
Keyword(s):  
Cross Sections ◽  
Mass Region ◽  
Scattering Data ◽  
Matrix Formalism ◽  
Scattering Parameters ◽  
Theoretical Evaluation ◽  
Least Squares Fit ◽  
Optical Model Potential ◽  
Nucleus Scattering ◽  
Scattering Lengths

AbstractSystematic calculations of the neutron-nucleus scattering parameters at several neutron energies Ei < 2 keV have been performed for 37 isotopes (6Li,... 59Co) in the mass region of 6 ≤ A ≤ 60, using the large compilation of experimental neutron-nucleus scattering data obtained in Garching. In the first stage of these calculations, the s-wave potential scattering radius R’, the scattering lengths bcoh, b±, and the bound state parameters (Eb, Γγ , gΓ0n) have been calculated for each isotope, employing the general least squares fit (GLSQF) for the experimental and the corresponding theoretical values of the total neutron-nucleus cross sections σexptot(Ei) at several energies Ei, absorption cross sections σabs(Eo) and of the coherent scattering lengths bcoh. The theoretical expressions for these parameters were deduced on the basis of the usual S-matrix formalism with no assumption about the particular shape of the optical model potential. In the second stage of our calculations, the spherical Fiedeldey- Frahn optical potential was employed for the pure theoretical description or the above mentioned neutron-nucleus scattering characteristics. The results obtained have been analyzed and compared with the values deduced from measurements.

scholarly journals Recent Developments in Neutrino/Antineutrino-Nucleus Interactions

2012 ◽  
Vol 2012 ◽  
pp. 1-35 ◽  
Author(s):  
Jorge G. Morfín ◽  
Juan Nieves ◽  
Jan T. Sobczyk
Keyword(s):  
Energy Range ◽  
Cross Sections ◽  
Scattering Data ◽  
Theoretical Treatment ◽  
Quasielastic Scattering ◽  
Current Contribution ◽  
The Status ◽  
Recent Developments ◽  
Nucleus Scattering ◽  
Nuclear Effects

Recent experimental results and developments in the theoretical treatment of neutrino-nucleus interactions in the energy range of 1–10 GeV are discussed. Difficulties in extracting neutrino-nucleon cross sections from neutrino-nucleus scattering data are explained and significance of understanding nuclear effects for neutrino oscillation experiments is stressed. Detailed discussions of the status of two-body current contribution in the kinematic region dominated by quasielastic scattering and specific features of partonic nuclear effects in weak DIS scattering are presented.

scholarly journals TESTING 6,8He DENSITY DISTRIBUTIONS BY CALCULATIONS OF TOTAL REACTION CROSS-SECTIONS OF 6,8He+28Si

2004 ◽  
Vol 13 (03) ◽  
pp. 573-583 ◽  
Author(s):  
V. K. LUKYANOV ◽  
E. V. ZEMLYANAYA ◽  
S. E. MASSEN ◽  
Ch. C. MOUSTAKIDIS ◽  
A. N. ANTONOV ◽  
...  
Keyword(s):  
Cross Sections ◽  
Reaction Cross ◽  
Scattering Data ◽  
Total Reaction ◽  
Density Distributions ◽  
Intermediate Energies ◽  
Limit Model ◽  
Optical Limit ◽  
Nucleus Scattering ◽  
Reaction Cross Sections

Calculations of the 6,8 He +28 Si total reaction cross-sections at intermediate energies are performed on the basis of the Glauber–Sitenko microscopic optical-limit model. The target-nucleus density distribution is taken from the electron-nucleus scattering data, and the 6,8 He densities are used as they are derived in different models. The results of the calculations are compared with existing experimental data. The effects of the density tails of the projectile nuclei as well as the role of shell admixtures and short-range correlations are analyzed.

Confronting electron and neutrino–nucleus interactions: Can the axial mass anomaly be resolved?

2014 ◽  
Vol 23 (04) ◽  
pp. 1430005 ◽  
Author(s):  
Omar Benhar
Keyword(s):  
Cross Sections ◽  
Target Nucleus ◽  
Reaction Mechanisms ◽  
Short Review ◽  
Scattering Data ◽  
Final States ◽  
Neutrino Interactions ◽  
Axial Mass ◽  
Nucleus Scattering

Comparison between electron– and neutrino–nucleus scattering data suggests that the so-called axial mass anomaly — i.e., the large disagreement between the value of the nucleon axial mass extracted from the analysis of neutrino interactions with carbon and oxygen and that obtained from deuteron data — is a manifestation of the difficulties in the interpretation of the flux averaged neutrino cross-sections. In this short review, I discuss the role of reaction mechanisms leading to the excitation of two particle–two hole final states of the target nucleus, which are believed to be responsible for the observed excess of quasielastic events, and argue that taking into account their effect may help to reconcile the sizeably different values of the axial mass reported by the MiniBooNe and NOMAD Collaborations.

Neutron diffraction, inelastic scattering and the structure of amphiphiles and macromolecules in solution

1975 ◽  
Vol 345 (1640) ◽  
pp. 119-144 ◽  
Keyword(s):  
Neutron Diffraction ◽  
Inelastic Scattering ◽  
Cross Sections ◽  
Biological Molecules ◽  
Variation Method ◽  
Contrast Variation ◽  
Structure And Dynamics ◽  
Spin Resonance ◽  
Scattering Lengths ◽  
Scattering Cross Sections

The methods by which neutron diffraction and inelastic scattering may be used to study the structure and dynamics of solutions are reviewed, with particular reference to solutions of amphiphile and biological molecules in water. Neutron methods have particular power because the scattering lengths for protons and deuterons are of opposite sign, and hence there exists the possibility of obtaining variable contrast between the scattering of the aqueous medium and the molecules in it. In addition, the contrast variation method is also applicable to inelastic scattering studies whereby the dynamics of one component of the solution can be preferentially studied due to large and variable differences in the scattering cross sections. Both applications of contrast variation are illustrated with examples of amphiphile-water lamellar mesophases, diffraction from collagen, viruses, and polymer solutions. Inelastic scattering observations and the dynamics of water between the lamellar sheets allow microscopic measurements of the water diffusion along and perpendicular to the layers. The information obtained is complementary to that from nuclear magnetic resonance and electron spin resonance studies of diffusion.

Charge exchange reactions on medium and heavy mass targets at intermediate energies

2019 ◽  
Vol 35 (08) ◽  
pp. 2050045
Author(s):  
Pardeep Singh ◽  
Monika Singh ◽  
Neha Rani
Keyword(s):  
Charge Exchange ◽  
Cross Sections ◽  
Energy Charge ◽  
Impulse Approximation ◽  
Mass Region ◽  
Intermediate Energy ◽  
Exchange Reactions ◽  
Plane Wave Impulse Approximation ◽  
Text Type ◽  
Intermediate Energies

The nuclear isotopic structure can be understood easily via the intermediate-energy charge exchange reactions of (p, n) and [Formula: see text]He, [Formula: see text] type. In the current contribution, we present some results for charge exchange reactions induced by 3He on targets lying in mass region [Formula: see text] within the theoretical framework of plane wave impulse approximation (PWIA) and distorted wave impulse approximation (DWIA). Here, the recoil effects in PWIA have also been considered. Particularly, the angular distributions and the unit cross-sections have been calculated and compared with the available data. Further, the importance of inclusion of the exchange contribution in these reactions is also considered, which eventually enhance the matching with data.

Theory of pion-nucleus scattering lengths

1977 ◽  
Vol 283 (4) ◽  
pp. 397-400 ◽  
Author(s):  
D. S. Koltun ◽  
F. Myhrer
Keyword(s):  
Nucleus Scattering ◽  
Scattering Lengths

scholarly journals Cramér-Rao Bound Study of Multiple Scattering Effects in Target Separation Estimation

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Edwin A. Marengo ◽  
Paul Berestesky
Keyword(s):  
Multiple Scattering ◽  
Born Approximation ◽  
Single Scattering ◽  
Scattering Data ◽  
Approximation Model ◽  
Scattering Parameters ◽  
Helmholtz Operator ◽  
Scattering Effects ◽  
Cramer Rao Bound ◽  
Multiple Scattering Effects

The information about the distance of separation between two-point targets that is contained in scattering data is explored in the context of the scalar Helmholtz operator via the Fisher information and associated Cramér-Rao bound (CRB) relevant to unbiased target separation estimation. The CRB results are obtained for the exact multiple scattering model and, for reference, also for the single scattering or Born approximation model applicable to weak scatterers. The effects of the sensing configuration and the scattering parameters in target separation estimation are analyzed. Conditions under which the targets' separation cannot be estimated are discussed for both models. Conditions for multiple scattering to be useful or detrimental to target separation estimation are discussed and illustrated.

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