The magnetic dipole moment of the Δ+(1232) resonance

The magnetic dipole moment of the Δ+(1232) resonance is a fundamental observable
and provides a stringent test of baryons structure calculations. A pioneering measurement
was performed in year 2002 and delivered a result of (2.7 ± 2.2 (exp)) μN
1.
However, a higher precision is needed to allow a clear selection between different structure
models.
A new dedicated experiment using the Crystal Ball and TAPS detectors has been performed 2004/2005
at MAMI, offering a superior 4π-acceptance and particle identification.
Exploiting the circular and linear polarized photon beam, two polarization observables
Σand Σcirc and in addition differential cross sections will be extracted.
The progress in the development of the theoretical calculations 2 3 4 allows a well directed interpretation
of the data in order to describe the reaction γ p → π0 γ ' p and to extract the magnetic
dipole moment.