Low-energy pion photoproduction from p-shell nuclei

1990 ◽  
Vol 68 (11) ◽  
pp. 1270-1278 ◽  
Author(s):  
C. Bennhold ◽  
L. Tiator ◽  
L. E. Wright

Low-energy pion photoproduction off 6Li, 10B, and 14N has been reinvestigated in a DWIA framework that includes a number of improvements neglected in previous analyses. The production operator is based on Feynman diagrams and includes correction terms of order p2/M2 and higher. An s-channel delta resonance term is included with both longitudinal and transverse electromagnetic couplings. Rather than using on harmonic oscillator for the nucleon orbitals we employ Woods–Saxon wave functions that have been adjusted to fit electron-scattering form factors and single-particle binding energies. Furthermore, we include the Coulomb potential without approximation in our momentum-space approach. Using more realistic wave functions and including corrections to the production amplitude that have been neglected before leads to considerable improvement in the case of 10B and 14N when compared with existing data. The Coulomb effects are shown to change the cross section by about 30% close to threshold but are negligible at higher energies.

1990 ◽  
Vol 41 (6) ◽  
pp. 2852-2864 ◽  
Author(s):  
H. W. L. Naus ◽  
J. H. Koch ◽  
J. L. Friar

2019 ◽  
pp. 1286-1296
Author(s):  
Rafah I. Noori ◽  
Arkan R. Ridha

In this work, the nuclear density distributions, size radii and elastic electron scattering form factors are calculated for proton-rich 8B, 17F, 17Ne, 23Al and 27P nuclei using the radial wave functions of Woods-Saxon potential. The parameters of such potential for nuclei under study are generated so as to reproduce the experimentally available size radii and binding energies of the last nucleons on the Fermi surface.


2018 ◽  
Vol 181 ◽  
pp. 01013 ◽  
Author(s):  
Reinhard Alkofer ◽  
Christian S. Fischer ◽  
Hèlios Sanchis-Alepuz

The covariant Faddeev approach which describes baryons as relativistic three-quark bound states and is based on the Dyson-Schwinger and Bethe-Salpeter equations of QCD is briefly reviewed. All elements, including especially the baryons’ three-body-wave-functions, the quark propagators and the dressed quark-photon vertex, are calculated from a well-established approximation for the quark-gluon interaction. Selected previous results of this approach for the spectrum and elastic electromagnetic form factors of ground-state baryons and resonances are reported. The main focus of this talk is a presentation and discussion of results from a recent investigation of the electromagnetic transition form factors between ground-state octet and decuplet baryons as well as the octet-only Σ0 to Λ transition.


1996 ◽  
Vol 05 (04) ◽  
pp. 717-724 ◽  
Author(s):  
D.N. KADREV ◽  
A.N. ANTONOV ◽  
M.V. STOITSOV ◽  
S.S. DIMITROVA

Natural orbitals obtained within the coherent density fluctuation model and containing nucleon correlation effects are used to calculate characteristics of the A-nucleon system, such as the electron elastic magnetic scattering form factors. The calculations are performed for nuclei with a doubly-closed core and a valence nucleon in a stretched configuration (j=l+1/2), such as the 17 O and 41 Ca nuclei. It is shown that the calculations of the transverse form factor using natural orbitals improve the agreement with the experimental data in comparison with the case when shell-model single-particle wave functions are used.


1994 ◽  
Vol 73 (3) ◽  
pp. 400-403 ◽  
Author(s):  
M. Benmerrouche ◽  
E. Tomusiak

The r. m. s. radius and the binding energy of oxygen 16 are calculated for several different internueleon potentials. These potentials all fit the low-energy data for two nucleons, they have hard cores of differing radii, and they include the Gammel-Thaler potential (core radius 0·4 fermi). The calculated r. m. s. radii range from 1·5 f for a potential with core radius 0·2 f to 2·0 f for a core radius 0·6 f. The value obtained from electron scattering experiments is 2·65 f. The calculated binding energies range from 256 MeV for a core radius 0·2 f to 118 MeV for core 0·5 f. The experimental value of binding energy is 127·3 MeV. The 25% discrepancy in the calculated r. m. s. radius may be due to the limitations of harmonic oscillator wave functions used in the unperturbed system.


Author(s):  
Lucas Happ ◽  
Matthias Zimmermann ◽  
Maxim A Efremov

Abstract We study a heavy-heavy-light three-body system confined to one space dimension in the regime where an excited state in the heavy-light subsystems becomes weakly bound. The associated two-body system is characterized by (i) the structure of the weakly-bound excited heavy-light state and (ii) the presence of deeply-bound heavy-light states. The consequences of these aspects for the behavior of the three-body system are analyzed. We find a strong indication for universal behavior of both three-body binding energies and wave functions for different weakly-bound excited states in the heavy-light subsystems.


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