A Note on Resonance Angular Distributions with Application to Nucleon?Antinucleon Scattering and Annihilation

Abstract

Angular distributions have been calculated for the reactions NN -+ NN and NN -+ 2 pseudoscalar mesons by assuming the formation of an intermediate isolated state. The scattering distributions are only found to have the characteristic oscillatory shape for unnatural parity resonances whereas those for natural parity states are smooth. The annihilation distributions display an exact degeneracy with respect to the interchange of orbital and total angular momenta. For both reactions, the width of the forward and backward peak is approximately inversely proportional to the resonance spin.