General formulation of covariant helicity-coupling amplitudes

A general formulation is given for constructing covariant helicity-coupling amplitudes involving two-body decays with arbitrary integer spins. The decay amplitudes are given exclusively in terms of both definite orbital angular momentum and total intrinsic Spin. A systematic method is developed for calculating the energy and momentum dependence of daughter particles in the decay amplitudes, and a general formula for arbitrary integer spins is given. A number of illustrative examples is worked out, among which is that of the Higgs boson decay into two gauge bosons. [S0556-2821(97)03423-1].