The Reactionp ! 0 0 p and the Magnetic Dipole Moment of the 1232 Resonance

The complex structure of the nucleon is reflected in its rich excitation spectrum. Attempts to unravel the baryon structure have led to an impressive determination of the properties of the nucleon, e.g., polarizabilities, magnetic moments, and more general form factors. Additional and substantial insight in the parton structure of the nucleon has been gained through deep inelastic electron scattering. In contrast to that, the knowledge of the nucleon’s excited states is limited to the mass of the lowest resonances and its (iso)spin quantum numbers. However, to test the modeling of internal degrees of freedom of the excited states, measurements of static properties are required. In particular, the properties of the � � 1232� resonance are of considerable interest because of its prominent position in the excitation spectrum. In this context, the magnetic moment is an important observable for testing baryon structure calculations. Different predictions for the magnetic moment were made in several calculations [1– 4]. The magnetic moments of the baryon octet (N;� ; � ; � ) of the SU(3) flavor symmetry classification are known very accurately through spin precession measurements. However, for the decuplet baryons, only � � � has been determined,