Electromagnetic properties of baryons

Understand

We discuss the chiral behavior of nucleon and Delta(1232) electromagnetic properties within the framework of a SU(2) covariant baryon chiral perturbation theory.

• Our one-loop calculation is complete to the order p^3 and p^4/Delta with Delta as the Delta(1232)-nucleon energy gap.
• We show that the magnetic moment of a resonance can be defined through the linear energy shift only when an additional relation between the involved masses and the applied magnetic field strength is fulfilled.
• Singularities and cusps in the pion mass dependence of the Delta(1232) electromagnetic moments reflect a non-fulfillment.