Nucleon-nucleon Bremsstrahlung: off-energy-shell effects and meson-exchange currents

1991 ◽  
Author(s):  
Virginia R. Brown
Keyword(s):  
Nucleon Nucleon ◽  
Meson Exchange ◽  
Shell Effects ◽  
Energy Shell ◽  
Meson Exchange Currents

Magnetic form factors for a trinucleon system using different meson exchange nucleon–nucleon interactions

1993 ◽  
Vol 71 (9-10) ◽  
pp. 455-461
Author(s):  
Ahmed Osman ◽  
M. Zaky ◽  
M. A. Allam
Keyword(s):  
Experimental Data ◽  
Momentum Transfer ◽  
Form Factors ◽  
Nucleon Nucleon ◽  
Meson Exchange ◽  
Current Conservation ◽  
Meson Theory ◽  
Transfer Region ◽  
Magnetic Form Factors ◽  
Meson Exchange Currents

The magnetic form factors for the 3He and 3H nuclei have been calculated for different values of momentum transfer. The three-nucleon ground-state wave function is expressed in momentum space and is obtained from the solution of the Faddeev equations with realistic two-body potentials. The potential used is taken from the meson theory to include different meson-exchange contributions satisfying the requirements of current conservation. The different meson-exchange currents and their contributions to the trinucleon magnetic form factors are calculated. The virtual Δ-excitation and the meson–nucleon vertices form factors are included in the 3He and 3H magnetic-form-factors calculations. The present results show the importance of the higher momentum transfer region as being a good source of information to the short-range processes in the nuclear medium. Our results for the 3He and 3H magnetic form factors are in good agreements with the experimental data. The inclusion of the ρ and ω meson exchanges improves the agreement between positions of the minima of the magnetic form factors predicted and the experimental data.

scholarly journals A Six-Quark Dressed-Bag Description of np→dγ Radiative Capture

2003 ◽  
Vol 12 (04) ◽  
pp. 449-478 ◽  
Author(s):  
M. M. Kaskulov ◽  
P. Grabmayr ◽  
V. I. Kukulin
Keyword(s):  
Cross Sections ◽  
Radiative Capture ◽  
Form Factors ◽  
Nucleon Nucleon ◽  
Pion Exchange ◽  
Exchange Current ◽  
Meson Exchange ◽  
Capture Process ◽  
Nucleon Nucleon Interaction ◽  
Meson Exchange Currents

The radiative capture process np→dγ is considered within the framework of a recently developed six-quark dressed-bag model for the nucleon-nucleon interaction. The calculations presented here include both the nucleon current and the meson-exchange current contributions. The latter uses short-range hadronic form factors for the pion exchange currents consistent with the soft cut-off parameter ΛπNN from the NN-potential. Contributions of the pion exchange current and Δ-isobar current to the total cross-section still cannot explain the discrepancy between the theoretical and experimental cross-sections. Possibilities for new types of meson exchange currents associated with chiral fields inside multi-quark dressed-bag states in nuclei are discussed.

RadiativenpCapture and Meson Exchange Currents

1971 ◽  
Vol 3 (6) ◽  
pp. 2498-2498 ◽  
Author(s):  
Ronald J. Adler ◽  
Benson T. Chertok ◽  
Henry C. Miller
Keyword(s):  
Meson Exchange ◽  
Meson Exchange Currents

scholarly journals Density dependence of 2p-2h meson-exchange currents

2017 ◽  
Vol 95 (6) ◽  
Author(s):  
J. E. Amaro ◽  
M. B. Barbaro ◽  
J. A. Caballero ◽  
A. De Pace ◽  
T. W. Donnelly ◽  
...  
Keyword(s):  
Density Dependence ◽  
Meson Exchange ◽  
Meson Exchange Currents

scholarly journals Meson-exchange currents and quasielastic neutrino cross sections in the superscaling approximation model

2011 ◽  
Vol 696 (1-2) ◽  
pp. 151-155 ◽  
Author(s):  
J.E. Amaro ◽  
M.B. Barbaro ◽  
J.A. Caballero ◽  
T.W. Donnelly ◽  
C.F. Williamson
Keyword(s):  
Cross Sections ◽  
Meson Exchange ◽  
Approximation Model ◽  
Meson Exchange Currents

Relativistic shell models and meson-exchange currents

1987 ◽  
Vol 475 (4) ◽  
pp. 720-742 ◽  
Author(s):  
J. Delorme ◽  
I.S. Towner
Keyword(s):  
Meson Exchange ◽  
Shell Models ◽  
Meson Exchange Currents

scholarly journals Consistent Treatment of Pion Exchange Force and Meson versus Quark Dynamics in the Nucleon?Nucleon Interaction

1993 ◽  
Vol 46 (6) ◽  
pp. 737
Author(s):  
GQ Liu ◽  
AW Thomas
Keyword(s):  
Vector Meson ◽  
Short Range ◽  
Coupling Model ◽  
Nucleon Nucleon ◽  
Pion Exchange ◽  
Meson Exchange ◽  
Exchange Potential ◽  
Exchange Force ◽  
Gluon Exchange ◽  
Vector Meson Exchange

To distinguish explicit quark effects from meson exchange in the NN interaction, it is necessary to splice the long-range meson exchange forces and short-distance dynamics due to quarks. However, in most quark model studies the short-range part of the pion exchange is usually treated differently, which makes it difficult to get a uniform picture of the short-range dynamics. We make a comparison between meson exchange and quark-gluon dynamics using the same pion exchange potential based on a quark-pion coupling model. The roles of vector meson exchange and gluon exchange in the NN interaction are compared by calculating NN phase parameters. It is shown that, with this consistent one-pion exchange force, the vector meson exchange gives a better fit to the data. This suggests that non-perturbative mechanisms responsible for meson exchange may need more careful handling to supplement the usual one-gluon exchange mechanism in describing the NN interaction.

scholarly journals PRESENT STATUS OF ELECTROMAGNETIC REACTIONS ON THE DEUTERON ABOVE PION THRESHOLD

2003 ◽  
Vol 18 (02n06) ◽  
pp. 190-199 ◽  
Author(s):  
H. ARENHÖVEL ◽  
E. M. DARWISH ◽  
A. FIX ◽  
M. SCHWAMB
Keyword(s):  
Present Status ◽  
Final State Interaction ◽  
Cloud Model ◽  
Resonance Region ◽  
Theoretical Description ◽  
Meson Exchange ◽  
Deuteron Photodisintegration ◽  
Final State ◽  
Shell Effects ◽  
Pion Threshold

The present status of the theoretical description of electromagnetic reactions on the deuteron above pion threshold is reviewed. Three major topics are considered: (i) retardation effects in π-meson exchange contributions to NN-interaction and meson exchange currents in deuteron photodisintegration above π-threshold in the Δ-resonance region, (ii) off-shell effects in the one-body current treated in a simple pion cloud model in, deuteron photodisintegration in and above the Δ-resonance region, and (iii) final state interaction effects in photoproduction of π and η mesons on the deuteron.

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