Speaker
Description
There is considerable phenomenological insight into the flavor compositions of nucleon electromagnetic form factors from elastic electron scattering on both the proton and the neutron at low and moderate momentum transfers. The flavor contents extracted so far from the corresponding world data sets impose severe tests on any theoretical description of the electromagnetic structure of the nucleons.
I shall discuss the predictions for covariant electric and magnetic form factors by a relativistic constituent-quark model and compare them to phenomenology as well as some results from lattice quantum chromodynamics. The main findings are that valence-quark contributions play the essential roles up to momentum transfers of q^2 ~ 4 GeV^2 and additional degrees of freedom, e.g., sea-quark effects, are still absent or at least negligible in this domain.
The same kind of studies is extended to the Δ and the hyperons showing interesting effects depending on the flavor structures of the particles belonging to either singlet, octet, and decuplet flavor multiplets as well as their admixtures.