Invariant amplitudes for coherent electromagnetic pseudoscalar production from a spin-one target, II: Crossing, multipoles, and observables

The formal properties of the recently derived set of linearly independent i nvariant amplitudes for the electromagnetic production of a pseudoscalar pa rticle from a spin-one particle have been further exploited. The crossing p roperties are discussed in detail. Since not all of the amplitudes have sim ple crossing behaviour, we introduce an alternative set of basic amplitudes which are either symmetric or antisymmetric under crossing. The multipole decomposition is given, and the representation of the multipoles as integra ls over the invariant functions weighted with Legendre polynomials is deriv ed. Furthermore, differential cross section and polarization observables ar e expressed in terms of the corresponding invariant functions.