Nuclear structure dependence in analyzing powers?

1980 ◽  
Vol 58 (12) ◽  
pp. 1686-1690 ◽  
Author(s):  
W. R. Falk

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.

1979 ◽  
Vol 57 (11) ◽  
pp. 1949-1951 ◽  
Author(s):  
M. A. M. Shahabuddin ◽  
J. C. Waddington

In the [Formula: see text] Al reaction at Ep = 17.0 MeV, the cross section and analyzing power angular distributions for several Jπ = 5/2+ states are found to be quite different. Except for the ground state, neither the back angle cross sections nor the analyzing powers for these states can be reproduced by cluster DWBA or CCBA calculations. It is thus inferred that this might be due to the dependence of the reaction on the structure of these states.


2012 ◽  
Vol 9 (3) ◽  
pp. 554-558 ◽  
Author(s):  
Baghdad Science Journal

The differential cross section for the Rhodium and Tantalum has been calculated by using the Cross Section Calculations (CSC) in range of energy(1keV-1MeV) . This calculations based on the programming of the Klein-Nashina and Rayleigh Equations. Atomic form factors as well as the coherent functions in Fortran90 language Machine proved very fast an accurate results and the possibility of application of such model to obtain the total coefficient for any elements or compounds.


2010 ◽  
Vol 19 (05n06) ◽  
pp. 894-902 ◽  
Author(s):  
L. P. KAPTARI ◽  
B. KÄMPFER

The production of pseudo scalar, η, η′, and vector, ω, ρ, ϕ, mesons in NN collisions at threshold-near energies is analyzed within a covariant effective meson-nucleon theory. It is shown that a good description of cross sections and angular distributions, for vector meson production, can be accomplished by considering meson and nucleon currents only, while for pseudo scalar production an inclusion of nucleon resonances is needed. The di-electron production from subsequent Dalitz decay of the produced mesons, η′ → γγ* → γe+e- and ω → πγ* → πe+e- is also considered and numerical results are presented for intermediate energies and kinematics of possible experiments with HADES, CLAS and KEK-PS. We argue that the transition form factor ω → γ*π as well as η′ → γ*γ can be defined in a fairly model independent way and the feasibility of an experimental access to transition form factors is discussed.


1987 ◽  
Vol 65 (6) ◽  
pp. 574-577 ◽  
Author(s):  
J. Rapaport

The (p, n) reaction at intermediate energies has been used to measure differential cross sections in light nuclei to final states characterized with a ΔJπ = 1+ transfer (Gamow–Teller (GT) states). Experimental ft values for allowed beta-decay transitions in these nuclei are used to normalize the strength of the GT transitions in units of B(GT). This experimental GT strength is compared with predicted shell–model strength. For p-shell nuclei, the calculated excitation energies of the GT strength using Cohen and Kurath wave functions are in general agreement with the empirical GT distribution. Up to an excitation energy of about 20 MeV, the total experimental and calculated GT strengths are used to obtain the quenching factor, QF = Σ B(GT)exp/Σ B(GT)theor. It is found that QF decreases as the shell gets filled-up. The lowest value seems to occur for single-hole nuclei. This decrease may be explained by configuration mixing not specifically included in the calculations.


1979 ◽  
Vol 57 (4) ◽  
pp. 540-549 ◽  
Author(s):  
R. de Swiniarski ◽  
Dinh-Lien Pham ◽  
G. Bagieu ◽  
H. V. Geramb

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.


2015 ◽  
Vol 24 (01) ◽  
pp. 1550006 ◽  
Author(s):  
Yuan Tian ◽  
Dan-Yang Pang ◽  
Zhong-Yu Ma

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.


1973 ◽  
Vol 28 (10) ◽  
pp. 1642-1653
Author(s):  
G.-P. Raabe

Scattering processes of atoms, molecules and ions with two crossing electronic potentials may be treated in the Stueckelberg-Landau-Zener-(SLZ) model. In this paper the WKB-solutions for the radial wave functions, given by Stueckelberg are used to calculate differential cross sections. The effects on the cross sections are explained in a semiclassical picture, following the procedures of Ford and Wheeler, and Berry. In the scattering of H+ by rare gases, some effects in the elastic cross sections are observed which can be explained by the influence of the potential of the chargeexchanged particles, using the SLZ-model. The structure in the elastic cross sections for H2+-Kr can be explained as a rainbow structure with superimposed Stueckelberg oscillations.


1963 ◽  
Vol 41 (7) ◽  
pp. 1036-1046 ◽  
Author(s):  
L. van der Zwan ◽  
A. T. Stewart ◽  
J. Y. Park ◽  
E. Merzbacher

The energy spectra and angular distributions of the emergent neutrons from the Be9(He3, n)C11 reaction have been obtained for an incident He3-particle energy of 2 Mev with the technique of observing proton recoil in photographic emulsions. The cross sections were normalized to Be9(He3, p)B11 data observed simultaneously at 90° to the beam. The lack of similarity in the (He3, n) and (He3, p) mirror reactions to some residual states suggests a direct interaction mechanism rather than compound nucleus. An attempt to analyze some of the data in terms of double particle stripping has been made.


2011 ◽  
Vol 26 (03n04) ◽  
pp. 677-678
Author(s):  
MARTA ŁUSZCZAK ◽  
ANTONI SZCZUREK

The cross sections for exclusive D+D- meson pair production in nucleus - nucleus collisions are calculated and differential distributions are shown. Realistic (Fourier transform of the charge density) charge form factors of nuclei are used. Absorption effects are included. Predictions for the STAR and PHENIX collaboration measurements at RHIC are presented.


2021 ◽  
pp. 11-16
Author(s):  
Rusudan Golyatina ◽  
Sergei Maiorov

Consideration is given to the analysis of data on the cross sections of elastic and inelastic col-lisions of electrons with noble gas atoms. The transport (diffusion) cross section, the excita-tion and ionization cross sections are studied. For the selected sets of experimental and theo-retical data, optimal analytical formulas are found and approximation coefficients are select-ed for them. The obtained semi-empirical formulas allow us to reproduce the cross section values in a wide range of collision energies from 0.001 to 10000 eV with an accuracy of sev-eral percent.


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