Determination of the Δ++ magnetic dipole moment

We study the elastic and radiative pi (+)p scattering within a full dynamical model which incorporates the finite width effects of the Delta (++). The scattering amplitudes are invariant under contact transformations of the spin 3/2 field and gauge-invariance is fulfilled for the radiative case. The pole parameters of the Delta (++) obtained from the elastic cross section are m(Delta) = (1211.2 +/- 0.4) MeV and Gamma (Delta) = (88.2 +/- 0.4) MeV. From a fit to the most sensitive observables in radiative Delta (++) scattering, we obtain mu (Delta) = (6.14 +/- 0.51)e/2m(p) for the magnetic dipole moment of the Delta (++). (C) 2001 Elsevier Science B.V. All rights reserved.