CCAST, World Lab, Beijing 100080, Peoples R China
; CAS, Inst High Energy Phys, Beijing 100039, Peoples R China
; Abdus Salam Int Ctr Theoret Phys, Trieste, Italy
For excited nucleon states N-* of arbitrary spin coupling to nucleon (N) and meson (M), we propose a Lorentz covariant orbital-spin (L-S) scheme for the effective (NNM)-N-* couplings. To be used for the partial wave analysis of various N-* production and decay processes, it combines merits of two conventional schemes, i.e., covariant effective Lagrangian approach and multipole analysis with amplitudes expanded according to angular momentum L. As examples, explicit formulas are given for N*-->Npi, N*-->Nomega, and psi-->N-*(N) over bar processes which are under current experimental studies.