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Results of recent theoretical studies on the electromagnetic form factors of strange baryons and kaons are embodied in a strangeness electromagnetic production model based on an effective Lagrangian approach. The sensitivity of different observables that are the subject of current or planned measurements at JLAB, are investigated with respect to the phenomenological ingredients of the model.

Previous approaches to the photo- and electro-production of strangeness on the proton, based upon effective Lagrangian, is extended to incorporate the so called off-shell effects (OSE) required while dealing with spin ⩾3/2 baryonic resonances. Results for K+ Λ channels are presented.

A formalism, based on an isobaric approach using Feynman diagrammatic techniques, which includes the nucleonic (spin \ensuremath{\le} 5/2), hyperonic (spin 1/2), and kaonic resonances, is developed. Using this formalism, a thorough investigation of the following electromagnetic strangeness processes, for which experimental results are available, is performed: \ensuremath{\gamma}p\ensuremath{\rightarrow}${\mathit{K}}^{+}$\ensuremath{\Lambda}, ${\mathit{K}}^{+}$${\mathrm{\ensuremath{\Sigma}}}^{0}$, ${\mathit{K}}^{0}$${\mathrm{\ensuremath{\Sigma}}}^{+}$, for ${\mathit{E}}_{\ensuremath{\gamma}}^{\mathrm{lab}}$\ensuremath{\le} 2.1 GeV, ep\ensuremath{\rightarrow}${\mathit{e}}^{\ensuremath{'}}$${\mathit{K}}^{+}$\ensuremath{\Lambda}, ${\mathit{e}}^{\ensuremath{'}}$${\mathit{K}}^{+}$${\mathrm{\ensuremath{\Sigma}}}^{0}$, and ${\mathit{K}}^{\mathrm{\ensuremath{-}}}$p\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\Lambda},\ensuremath{\gamma}${\mathrm{\ensuremath{\Sigma}}}^{0}$. A reaction mechanism, describing well enough the data, is found to include a reasonable number of baryonic resonances among a very large number of potential candidates. The extracted main kaon-hyperon-nucleon coupling constants are in good agreement with values predicted using SU(3) symmetry. The main findings of this model are compared with the results of other recent phenomenological studies. Predictions for the upcoming photoproduction polarization and electroproduction observables are presented, and their sensitivity to the phenomenological models ingredients are emphasized. \textcopyright{} 1996 The American Physical Society.

A formalism, based on an isobaric approach, via Feynman diagrammatic technique, including the nucleonic (spin ≤ 5/2), hyperonic (spin 1/2) and kaonic resonances is developed. Using this formalism, a thorough investigation of all the electromagnetic strangeness processes, for which experimental results are available, is performed and satisfactory agreement with the data is obtained. The reaction mechanism is found to include a reasonable number of baryonic resonances, with the extracted main kaon-hyperon-nucleon coupling constants in agreement with the SU(3)-symmetry predictions. The sensitivity of this model to the form factors of the relevant hadrons is emphasized.

Investigations in progress on the associated strangeness photo‐ and electroproduction of the proton in the few GeV region and the negative kaon radiative capture are reported, and results for the K+∑0 channel are presented.

This chapter focuses on Coulomb energy of 3 He. The AGS quasiparticle method provides a way to include the Coulomb interaction in the three-nucleon system, especially, as demonstrated by Alessandrini and Zankel, if only two charged nucleons are present in the three-body system. The method takes into account the Coulomb force exactly, and so the usual Coulomb singularity problem arises. As there is still no manageable exact treatment of the Coulomb many-body system available, the Coulomb singularity is circumvented by using a Yukawa type cutoff. Considering the small internucleon distances in the three-nucleon bound state, it seems to be plausible that the long-range Coulomb singularity rather weakly influences the three-nucleon binding energy. Switching off all Coulomb contributions in the 3 He, assuming charge symmetry of the nuclear forces, a model is obtained for the triton. The binding energy difference of 3 H and 3 He is then the Coulomb energy ( E C ) of He. The chapter illustrates the effective potential of 3 He.

We show the great sensitivity of the πd elastic-scattering observables to the details of the deuteron wave function. At 142 MeV and 256 MeV we find that the differential cross-section at θc.m.=180° depends linearly upon the quantityA(q2), which is the most important part of the deuteron electromagnetic form factor. A similar behaviour appears for the tensor polarizationt20(180°) at 142 MeV. Our results are compared with existing experimental data at backward angles.