Charge-Exchange Scattering of Pions on 14N

1971 ◽  
Vol 49 (13) ◽  
pp. 1826-1827 ◽  
Author(s):  
Arlene P. Maclin ◽  
J. M. Eisenberg
Keyword(s):  
Experimental Data ◽  
Shell Model ◽  
Charge Exchange ◽  
Cross Sections ◽  
Theoretical Calculations ◽  
Impulse Approximation ◽  
Wave Functions ◽  
Exchange Scattering ◽  
Low Amplitude ◽  
Model Formalism

Cross sections for the reaction 14N(π+,π0)14O are calculated near the (3, 3) resonance using the impulse approximation together with the Chew–Low amplitude in the framework of a two-hole shell model formalism. Various sets of wave functions are used and comparisons are made with existing experimental data and other theoretical calculations.

Photoproduction of positive pions from 16O at medium energies

1980 ◽  
Vol 58 (8) ◽  
pp. 1151-1162 ◽  
Author(s):  
V. Devanathan ◽  
V. Girija ◽  
G. N. Sivarama Prasad
Keyword(s):  
Experimental Data ◽  
Nuclear Structure ◽  
Cross Sections ◽  
Impulse Approximation ◽  
Wave Functions ◽  
Fair Agreement ◽  
Free Nucleon ◽  
Distorted Wave ◽  
Distorted Wave Impulse Approximation ◽  
Γ Ray

The reaction 16O(γ,π+)16N has been studied in the distorted wave impulse approximation (DWIA) using the free-nucleon photopion amplitude. The nuclear distortion effects on the emitted pion and also the effect of nuclear structure are investigated in detail. The effect of nuclear distortion is found to be small at lower energies but is of great importance resulting in large absorption of pions around the (3,3) resonance. Using realistic nuclear wave functions, it is found that the DWIA yields cross sections in fair agreement with the experimental data at γ-ray energies above 230 MeV but higher values at lower energies.

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.

Cross sections for d-3H neutron interactions with samarium isotopes

2016 ◽  
Vol 104 (8) ◽  
Author(s):  
Junhua Luo ◽  
Chunlei Wu ◽  
Li Jiang ◽  
Long He
Keyword(s):  
Experimental Data ◽  
Neutron Flux ◽  
Cross Sections ◽  
Theoretical Calculations ◽  
Nuclear Model ◽  
Activation Technique ◽  
Incident Neutron ◽  
Reaction Threshold ◽  
Talys 1.6 ◽  
The Cross

Abstract:The cross sections for (n,x) reactions on samarium isotopes were measured at (d-T) neutron energies of 13.5 and 14.8 MeV with the activation technique. Samples were activated along with Nb and Al monitor foils to determine the incident neutron flux. Theoretical calculations of excitation functions were performed using the nuclear model codes TALYS-1.6 and EMPIRE-3.2 Malta with default parameters, at neutron energies varying from the reaction threshold to 20 MeV. The results were discussed and compared with experimental data found in the literature. At neutron energies 13.5 and 14.8 MeV, the cross sections of the

Pseudopotential calculations of elastic scattering of electrons by helium atoms in the range 0–20 eV

1990 ◽  
Vol 68 (1) ◽  
pp. 104-110 ◽  
Author(s):  
B. Plenkiewicz ◽  
P. Plenkiewicz ◽  
J.-P. Jay-Gerin
Keyword(s):  
Experimental Data ◽  
Elastic Scattering ◽  
Momentum Transfer ◽  
Cross Sections ◽  
Theoretical Calculations ◽  
Incident Electron ◽  
Elastic Electron ◽  
Scattering System ◽  
Helium Atoms ◽  
Pseudopotential Calculations

Our earlier pseudopotential calculations on electrons colliding with argon and krypton are extended to consider the elastic electron–helium scattering system. In this paper, we present detailed results for phase shifts, differential, total, and momentum-transfer cross sections for this system for incident electron energies in the range from 0 to 20 eV. These agree very well with existing experimental data and with other theoretical calculations.

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.

The octupole deformation of 143Ba

2015 ◽  
Vol 24 (11) ◽  
pp. 1550081 ◽  
Author(s):  
Yong-Jing Chen ◽  
Yong-Shou Chen ◽  
Zao-Chun Gao ◽  
Ya Tu
Keyword(s):  
Experimental Data ◽  
Shell Model ◽  
Ground State ◽  
Wave Functions ◽  
Rotational Bands ◽  
Octupole Deformation ◽  
Quantum Numbers

Based on existence of the octupole deformation in the intrinsic states, the experimentally observed four rotational bands in [Formula: see text]Ba have been well reproduced by the reflection asymmetric shell model (RASM) calculations. Through the analysis of the calculated RASM wave functions, the intrinsic configuration of the observed rotational bands has been assigned as the octupole deformed neutron [Formula: see text] orbit, which is just located below the [Formula: see text] shell gap. The calculated results supported the ground state octupole deformation and the purity of the simplex quantum numbers [Formula: see text] in [Formula: see text]Ba. In addition, the calculated [Formula: see text] values are in agreement with experimental data, and further support the octupole deformation in [Formula: see text]Ba.

First-order exchange approximation

1963 ◽  
Vol 276 (1366) ◽  
pp. 346-353 ◽  
Keyword(s):  
Elastic Scattering ◽  
Cross Sections ◽  
Born Approximation ◽  
Scattering Amplitude ◽  
Wave Functions ◽  
Hydrogen Atoms ◽  
Final State ◽  
First Order ◽  
Exchange Approximation ◽  
Exchange Scattering

It is shown that when the Born approximation is applied to rearrangement collisions in the customary way, terms of the first order in the interaction energy between the colliding particles are omitted from the exchange scattering amplitude. If these terms are retained the arbitrariness which arises from the lack of orthogonality between the initial and final state wave functions is removed. The first-order exchange approximation derived in the present paper is employed to calculate the cross-sections for the 1 s -2 s and 1 s -2 p excitations of hydrogen atoms by electron impact and the elastic scattering of electrons by hydrogen atoms.

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