Physics – Nuclear Physics – Nuclear Theory
Scientific paper
2007-12-14
Phys.Rev.C77:045205,2008
Physics
Nuclear Physics
Nuclear Theory
Corrected version. 14 pages, 10 figures
Scientific paper
10.1103/PhysRevC.77.045205
The electromagnetic pion production reactions are investigated within the dynamical coupled-channels model developed in {\bf Physics Reports, 439, 193 (2007)}. The meson-baryon channels included in this study are $\gamma N$, $\pi N$, $\eta N$, and the $\pi\Delta$, $\rho N$ and $\sigma N$ resonant components of the $\pi\pi N$ channel. With the hadronic parameters of the model determined in a recent study of $\pi N$ scattering, we show that the pion photoproduction data up to the second resonance region can be described to a very large extent by only adjusting the bare $\gamma N \to N^*$ helicity amplitudes, while the non-resonant electromagnetic couplings are taken from previous works. It is found that the coupled-channels effects can contribute about 10 - 20 % of the production cross sections in the $\Delta$ (1232) resonance region, and can drastically change the magnitude and shape of the cross sections in the second resonance region. The importance of the off-shell effects in a dynamical approach is also demonstrated. The meson cloud effects as well as the coupled-channels contributions to the $\gamma N \to N^*$ form factors are found to be mainly in the low $Q^2$ region. For the magnetic M1 $\gamma N \to \Delta$ (1232) form factor, the results are close to that of the Sato-Lee Model. Necessary improvements to the model and future developments are discussed.
Julia-Diaz Bruno
Lee T. S. -H.
Matsuyama Akihiko
Sato Takeshi
Smith Laurence C.
No associations
LandOfFree
Dynamical Coupled-Channels Effects on Pion Photoproduction does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Dynamical Coupled-Channels Effects on Pion Photoproduction, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dynamical Coupled-Channels Effects on Pion Photoproduction will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-662188