Sum Rule Photodisintegration Cross Sections of 6Li

1974 ◽  
Vol 52 (3) ◽  
pp. 202-206
Author(s):  
H. L. Yadav ◽  
B. K. Srivastava
Keyword(s):  
Charge Distribution ◽  
Cross Sections ◽  
Sum Rules ◽  
Wave Functions ◽  
Radial Wave ◽  
Sum Rule ◽  
Dependent Potential ◽  
Good Agreement

We apply the sum rules of Levinger and Bethe to calculate the integrated [Formula: see text] cross sections for 6Li using the Gaussian and Irving forms of radial wave functions whose parameters are determined by fitting the r.m.s. radius of charge distribution in 6Li. For the potential in the σint calculation we use the central velocity-dependent potential of Herndon et al. Our results for σint and σb for 6Li show reasonably good agreement with experiments.

Sum Rule Photo-Disintegration Cross Sections for the Deuteron with Velocity-Dependent and Hard-Core Potentials

1971 ◽  
Vol 49 (17) ◽  
pp. 2211-2214 ◽  
Author(s):  
S. S. Raghavan ◽  
B. K. Srivastava
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Sum Rules ◽  
Hard Core ◽  
Dipole Approximation ◽  
Sum Rule ◽  
Core Potential ◽  
Cross Section Formula ◽  
Dependent Potential ◽  
Integrated Cross Section

We apply the sum rules of Levinger and Bethe to calculate the integrated cross section[Formula: see text]and the bremsstrahlung-weighted cross section[Formula: see text]for the deuteron in the dipole approximation. In our calculations we use (i) Nestor's velocity-dependent potential and (ii) Reid's hard-core potential. Our results for σint and σb obtained with the velocity-dependent potential of Nestor and the hard-core potential of Reid agree well with experiments.

scholarly journals INTEGRAL TRANSFORM TECHNIQUE FOR MESON WAVE FUNCTIONS

1996 ◽  
Vol 11 (20) ◽  
pp. 1611-1626 ◽  
Author(s):  
A.P. BAKULEV ◽  
S.V. MIKHAILOV
Keyword(s):  
Wave Function ◽  
Sum Rules ◽  
Integral Transform ◽  
Wave Functions ◽  
Sum Rule ◽  
New Approach ◽  
Exactly Solvable ◽  
The Stability ◽  
The Masses ◽  
Integral Transform Technique

In a recent paper1 we have proposed a new approach for extracting the wave function of the π-meson φπ(x) and the masses and wave functions of its first resonances from the new QCD sum rules for nondiagonal correlators obtained in Ref. 2. Here, we test our approach using an exactly solvable toy model as illustration. We demonstrate the validity of the method and suggest a pure algebraic procedure for extracting the masses and wave functions relating to the case under investigation. We also explore the stability of the procedure under perturbations of the theoretical part of the sum rule. In application to the pion case, this results not only in the mass and wave function of the first resonance (π′), but also in the estimation of π″-mass.

Direct Photodisintegration of 9Be in the Low and Sub-Giant Resonance Energy Region

1969 ◽  
Vol 24 (8) ◽  
pp. 1188-1195
Author(s):  
Terje Aurdal
Keyword(s):  
Cross Sections ◽  
Giant Resonance ◽  
Resonance Energy ◽  
Wave Functions ◽  
Nuclear Model ◽  
Final States ◽  
Core State ◽  
Radial Wave ◽  
Total Cross Sections ◽  
Reaction Channels

Abstract Photodisintegration cross sections for the reaction 9Be(γ,n) 8Be with photonenergies varied from threshold to about 17 MeV are calculated. As nuclear model is assumed a single particle shell model where the valence neutron outside the 8Be core is feeling a spherical field. The core state is assumed to be a mixture of the ground (0+) and the first excited (2+) state of the 8Be nucleus. The total cross sections are splitted up according to the different contributing reaction channels. The radial wave functions in initial as well as final states are of the Saxon-Woods type.

Gamow–Teller strength functions from scattering experiments

1987 ◽  
Vol 65 (6) ◽  
pp. 691-698 ◽  
Author(s):  
O. Häusser
Keyword(s):  
Shell Model ◽  
Cross Sections ◽  
Mean Field ◽  
Wave Functions ◽  
Structure Information ◽  
Model Wave ◽  
Spin Flip ◽  
Strength Functions ◽  
Gamow Teller ◽  
Good Agreement

We present here recent [Formula: see text] results from TRIUMF that are relevant to the determination of spin-flip isovector strength functions in nuclei. Distortion factors needed for the extraction of nuclear-structure information have been deduced from cross sections and analyzing powers in elastic scattering for several energies and targets. Nonrelativistic optical potentials obtained by folding effective nucleon (N)–nucleus interactions with nuclear densities are found to overpredict both elastic and reaction cross sections, whereas Dirac calculations that include Pauli blocking are in good agreement with the data. Spin observables (Snn and Ay) for the quasi-elastic region in 54Fe[Formula: see text] at 290 MeV provide some evidence for the reduction of the effective proton mass predicted in relativistic mean-field theories as a consequence of the attractive scalar field in the nuclear medium. The energy dependence of the effective N–nucleus interaction at small momentum transfers has been investigated using isoscalar and isovector 1+ states in 28Si as probe states. We find that the cross sections for the isovector transitions are in good agreement with predictions for the dominant Vστ part of the Franey–Love interaction. Gamow–Teller (GT) strength functions have been obtained in 24Mg and 54Fe from measurements of both cross sections and spin–flip probabilities Snn. The spin-flip cross sections σSnn are particularly useful in heavier nuclei to discriminate against a continuous background of ΔS = 0 excitations. In the (s, d) shell where full shell-model wave functions are available, the GT quenching factors [Formula: see text] are in good agreement with those from recent (p, n) and (n, p) experiments. We show that a state-by-state comparison of (p, p′) and (e, e′) results has the potential of identifying pionic current contributions in (e, e′). The GT quenching factors in 54Fe are smaller than in the (s, d) shell probably because of severely truncated shell-model wave functions, particularly those of the nuclear ground state.

scholarly journals STATUS OF THE HADRONIC τ DETERMINATION OF Vus

2008 ◽  
Vol 23 (21) ◽  
pp. 3191-3195 ◽  
Author(s):  
K. MALTMAN ◽  
C. E. WOLFE ◽  
S. BANERJEE ◽  
M. RONEY ◽  
I. NUGENT
Keyword(s):  
Sum Rules ◽  
Branching Fractions ◽  
Sum Rule ◽  
Slow Convergence ◽  
Decay Data ◽  
Decay Modes ◽  
Good Agreement

We update the extraction of Vus from hadronic τ decay data in light of recent BaBar and Belle results on the branching fractions of a number of important strange decay modes. A range of sum rule analyses is employed, particular attention being paid to those based on “non-spectral weights”, developed previously to bring the slow convergence of the relevant integrated D = 2 OPE series under improved control. Results from the various sum rules are in good agreement with one another, but ~ 3σ below expectations based on 3-family unitarity.

Stueckelberg-Landau-Zener-(SLZ)-Modell für atomare Stoßprozesse / Stueckelberg-Landau-Zener-(SLZ) Model for Atomic Scattering Processes

1973 ◽  
Vol 28 (10) ◽  
pp. 1642-1653
Author(s):  
G.-P. Raabe
Keyword(s):  
Cross Sections ◽  
Differential Cross ◽  
Wave Functions ◽  
Differential Cross Sections ◽  
Rare Gases ◽  
Radial Wave ◽  
Atomic Scattering ◽  
The Cross

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.

Many-Electron Correlations in the Photoionization of a Nitrogen Atom

1974 ◽  
Vol 52 (4) ◽  
pp. 349-354 ◽  
Author(s):  
N. A. Cherepkov ◽  
L. V. Chernysheva ◽  
V. Radojević ◽  
I. Pavlin
Keyword(s):  
Nitrogen Atom ◽  
Cross Section ◽  
Cross Sections ◽  
Random Phase Approximation ◽  
Random Phase ◽  
Electron Correlations ◽  
Sum Rule ◽  
Hartree Fock ◽  
The Cross ◽  
Good Agreement

Photoionization cross sections for the outer shell of the nitrogen atom ground state are calculated in the single-particle Hartree–Fock approximation and, in order to take into account many-electron correlations, also in the Random Phase Approximation with Exchange (RPAE). To be able to apply the RPAE, its modification for the half-filled shell atom, such as nitrogen atom, is presented. Calculation of length and velocity forms of the cross section in both approximations are compared with the available experimental data, and a good agreement is obtained. It has been found that in the RPAE the influence of many-electron correlations in a nitrogen atom is not great, but it is very important since, in contrast to the Hartree–Fock approximation, it results in the validity of the sum rule and the coincidence of the length and velocity forms of the cross sections, in agreement with the requirement of the general theory. The angular distribution of photoelectrons is also calculated in the RPAE, which has not been measured so far.

PHOTONEUTRON CROSS SECTIONS OF SOME ELEMENTS

1954 ◽  
Vol 32 (1) ◽  
pp. 49-59 ◽  
Author(s):  
J. Goldemberg ◽  
Leon Katz
Keyword(s):  
Statistical Theory ◽  
Cross Sections ◽  
Neutron Yield ◽  
Preceding Paper ◽  
Maximum Energy ◽  
Experimental Results ◽  
Sum Rule ◽  
Data Support ◽  
The University ◽  
Good Agreement

The neutron yield from photo-reactions in nine elements has been measured as a function of the maximum energy of the University of Saskatchewan Betatron. Cross sections are given for each of the reactions as calculated from these data. The integrated cross sections are compared with theoretical sum-rule predictions of Levinger and Bethe and good agreement is obtained with x = ½. The data support the conclusions reached in a preceding paper by Montalbetti, Katz, and Goldemberg. The competition between (γ, n) and (γ, p) reactions in chromium and in nickel is analyzed in the light of these experimental results. Good agreement with statistical theory is obtained in both cases.

scholarly journals Study of matter density distributions, elastic charge form factors and size radii for halo 11Be, 19C and 11Li nuclei

2018 ◽  
Vol 16 (36) ◽  
pp. 29-38
Author(s):  
Zaid M. Abbas
Keyword(s):  
Form Factors ◽  
Matter Density ◽  
Wave Functions ◽  
Saxon Potential ◽  
Radial Wave ◽  
Charge Form ◽  
Density Distributions ◽  
The Core ◽  
Core Part ◽  
Good Agreement

In this work, the calculation of matter density distributions, elastic charge form factors and size radii for halo 11Be, 19C and 11Li nuclei are calculated. Each nuclide under study are divided into two parts; one for core part and the second for halo part. The core part are studied using harmonic-oscillator radial wave functions, while the halo part are studied using the radial wave functions of Woods-Saxon potential. A very good agreement are obtained with experimental data for matter density distributions and available size radii. Besides, the quadrupole moment for 11Li are generated.

Helicity-dependent reaction γd → π0d near the η-threshold and its contribution to the E-asymmetry and the GDH sum rule for the deuteron

2015 ◽  
Vol 24 (08) ◽  
pp. 1550064 ◽  
Author(s):  
Eed M. Darwish ◽  
A. Hemmdan ◽  
N. T. El-Shamy
Keyword(s):  
Cross Sections ◽  
Potential Model ◽  
Spin Asymmetry ◽  
Deuteron Wave Function ◽  
Impulse Approximation ◽  
Wave Functions ◽  
Sum Rule ◽  
Higher Order Terms ◽  
Deuteron Spin ◽  
Gdh Sum Rule

The helicity-dependent coherent π0-photoproduction in the reaction γd → π0d near the η-threshold is investigated. The calculations are performed within an approach which includes the reaction amplitudes of the impulse approximation (IA), two-step process with intermediate πN- and ηN-rescattering, and the higher order terms in the multiple scattering series for the intermediate ηNN interaction. The contribution of γd → π0d to the deuteron spin asymmetry is calculated and its contribution to the Gerasimov–Drell–Hearn (GDH) integral is explicitly evaluated by integration up to a photon energy of 900 MeV. In addition, the helicity E-asymmetry is calculated. The results revealed that the doubly polarized differential cross-sections and the helicity E-asymmetry are sensitive to the interference of rescattering effects, specially at photon energies 600–800 MeV and extreme backward pion angles. The sensitivity of the obtained results for the GDH integral to the choice of NN potential model governing the deuteron wave function is discussed. We find that the deviation among results obtained for the deuteron GDH integral using different deuteron wave functions is quite large.

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