Transition from hadronic to partonic interactions for a composite spin-1/2 model of a nucleon
| dc.creator | Tjon, J. A. | |
| dc.creator | Wallace, S. J. | |
| dc.date | 2000-02-22 | |
| dc.date.accessioned | 2026-07-07T10:54:31Z | |
| dc.date.available | 2026-07-07T10:54:31Z | |
| dc.description | A simple model of a composite nucleon is developed in which a fermion and a boson, representing quark and diquark constituents of the nucleon, form a bound state owing to a contact interaction. Photon and pion couplings to the quark provide vertex functions for the photon and pion interactions with the composite nucleon. By a suitable choice of cutoff parameters of the model, realistic electromagnetic form factors are obtained. When a pseudoscalar pion-quark coupling is used, the pion-nucleon coupling is predominantly pseudovector. A virtual photopion amplitude is considered in which there are two types of contributions: hadronic contributions where the photon and pion interactions have an intervening propagator of the nucleon or its excited states, and contact-like contributions where the photon and pion interactions occur within a single vertex. At large Q, the contact-like contributions are dominant. The model nucleon exhibits scaling behavior in deep-inelastic scattering and the normalization of the parton distribution provides a rough normalization of the contact-like contributions. Calculations for the virtual photopion amplitude are performed using kinematics appropriate to its occurrence as a meson-exchange current in electron-deuteron scattering. The results show that the contact-like terms can dominate the meson-exchange current for Q > 1 GeV/c. There is a direct connection of the contact-like terms to the off-forward parton distributions of the model nucleon. | |
| dc.description | 24 pages, 19 postscript figures | |
| dc.identifier | https://arxiv.org/abs/nucl-th/0002051 | |
| dc.identifier | http://arxiv.org/abs/nucl-th/0002051 | |
| dc.identifier | Phys.Rev.C62:065202,2000 | |
| dc.identifier | doi:10.1103/PhysRevC.62.065202 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/185822 | |
| dc.subject | Nuclear Theory | |
| dc.title | Transition from hadronic to partonic interactions for a composite spin-1/2 model of a nucleon | |
| dc.type | text |