Production Mechanisms and Relations between Spin Density Matrix Elements

UCRL-18010 The spin structure of amplitudes for the production of a single baryon or meson resonance of arbitrary spin in a quasi-two-body final state has been investigated. If the dominant mechanism is the exchange of a single set of quantum numbers in the crossed channel, the spin density matrix elements are shown to satisfy bilinear relations. Typical relations are 2 2 (Re p ) + (Re p ) m,n m,-n for baryon production, and 2 (Re p + Re p ) m,n m,-n for meson production. It is suggested that the use of these relations in data analysis is a good test for the presence of two or more exchange contributions. The relations are used to analyze vector and tensor meson production from nN and KN initial states, and 6(1236) production from nN and NN initial states. Two of the most interesting results concern 6 production. We find that the small-angle data on NN ~ N6