0000000000713900
AUTHOR
M.m. Giannini
Electroproduction of hyperons
Abstract We present some estimates for the reaction ep → e ′ Σ + . At small scattering angles, the differential cross section is completely determined by the experimental data for the radiative decay Σ + → pγ . For kinematical values typical of the proposed parity experiment at MAMI, we find a suppression factor of about 5 · 10 −15 as compared to elastic electron scattering. On the basis of conservative models for the transition form factors, this ratio might increase by about a factor of 20 at backward angles. Even higher values could be expected if the presently unknown convection currents should turn out to be large. Due to the parity violation involved in this process, we also expect a …
Three-body forces in the quark model
The constituent quark model has been very useful for the description of many physical properties of baryons, achieving in most cases a fair agreement with the experimental data 1 The model is based on a non relativistic QCD-inspired dynamics including a harmonic oscillator (h.o.) confinement potential and a spin dependent (hyperfine) interaction. The use of Lovelace coordinates p, ~ avoides any problem with the center of mass motion, while the h.o. potential provides a simple basis for ana ly t ica l calculations, which is a very important feature for many applications, like the evaluation of form factors and Meson Exchange Currents 2. On the other hand the h.o. spectrum is too degenerate w…