Abstract
A simple analysis is given for the coupling of a pion to baryons of arbitrary spins and parities. The structure of the vertex depends on a new quantum number called γ parity. Recursion formulas are given relating high-spin vertices to lower spin vertices. The recursion formulas are solved to give explicit formulas for the πBB vertex when one baryon is at rest. New polynomials in the energy variable are introduced for this purpose. A symmetry relation is derived which connects vertex functions of opposite γ parity and opposite energy of the moving baryon. The isospin structure of the vertex is analyzed in order to obtain a standardized form useful in comparing effective coupling constants. "Transition isospin matrices" are introduced and their properties derived. General, explicit formulas for decay widths are given for arbitrary-spin transitions of the baryons. No trace calculations are required.