Dynamical Coupled-Channels Effects on Pion Photoproduction
| dc.creator | Julia-Diaz, B. | |
| dc.creator | Lee, T. -S. H. | |
| dc.creator | Matsuyama, A. | |
| dc.creator | Sato, T. | |
| dc.creator | Smith, L. C. | |
| dc.date | 2007-12-14 | |
| dc.date | 2008-01-07 | |
| dc.date.accessioned | 2026-07-07T11:13:45Z | |
| dc.date.available | 2026-07-07T11:13:45Z | |
| dc.description | 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 $γN$, $πN$, $ηN$, and the $πΔ$, $ρN$ and $σN$ resonant components of the $ππN$ channel. With the hadronic parameters of the model determined in a recent study of $πN$ 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 $γN \to N^*$ 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 $Δ$ (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 $γN \to N^*$ form factors are found to be mainly in the low $Q^2$ region. For the magnetic M1 $γN \to Δ$ (1232) form factor, the results are close to that of the Sato-Lee Model. Necessary improvements to the model and future developments are discussed. | |
| dc.description | Corrected version. 14 pages, 10 figures | |
| dc.identifier | https://arxiv.org/abs/0712.2283 | |
| dc.identifier | http://arxiv.org/abs/0712.2283 | |
| dc.identifier | Phys.Rev.C77:045205,2008 | |
| dc.identifier | doi:10.1103/PhysRevC.77.045205 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/191827 | |
| dc.subject | Nuclear Theory | |
| dc.title | Dynamical Coupled-Channels Effects on Pion Photoproduction | |
| dc.type | text |