Bruno Julia Diaz

University of Helsinki, Finland

Baryon Form Factors in Relativistic Constituent Quark Models


The electromagnetic and axial form factors of the nucleon and its lowest positive parity excitations, the Δ(1232) and the N(1440), are calculated with constituent-quark models that are specified by simple algebraic representations of the mass-operator eigenstates. Poincaré covariant current operators are generated by the dynamics from single-quark currents that are covariant under a kinematic subgroup. The dependence of the calculated form factors on the choice of kinematics and on the gross features of the wave functions is illustrated for instant-form, point-form, and front-form kinematics. A simple algebraic form of the orbital ground state wave function, which depends on two parameters,allows a fair description of all the form factors, although with widely different choices of the parameters, which determine the range and shape of the orbital wave function.

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