NUCLEON FORM-FACTORS IN A COVARIANT DIQUARK-QUARK MODEL

In a model where constituent quarks and diquarks interact through quar k exchange the Bethe-Salpeter equation in ladder approximation for the nucleon is solved. Quark and diquark confinement is effectively param etrized by choosing appropriately modified propagators. The coupling t o external currents is implemented via non-trivial vertex functions fo r quarks and diquarks to ensure gauge invariance at the constituent le vel. Nucleon matrix elements are evaluated in a generalized impulse ap proximation, and electromagnetic, pionic and axial form factors are ca lculated. (C) 1997 Elsevier Science B.V.