Partial decay widths of baryons in the spin-momentum operator expansion   method
  The cross sections for photo- and pion-induced production of baryon resonances and their partial decay widths to the two--body and multi--body final states are calculated in the framework of the operator expansion method. The approach is fully relativistic invariant, and it allows us to perform combined analyses of different reactions imposing directly the analyticity and unitarity constraints. All formulae are given explicitly in the form used by the Crystal Barrel collaboration in the partial wave analysis. 
A.V.Anisovich and A.V.Sarantsev