High-Spin Baryons. IV. Decay Modes and Possible Regularities

Abstract

Effective coupling constants for decays of the type baryon → baryon plus pseudoscalar meson are derived from experiment. In the absence of a reliable theory of the structure (barrier-penetration factor), we are unable to attribute an intrinsic meaning to these couplings. However, for the pion-nucleon system we tentatively suggest the existence of several approximate rules. With appropriate definitions of the couplings, these are as follows: (1) The $\pi \mathrm{BB}$ coupling is independent of the baryon $B$; (2) decays down a trajectory have a strength independent of trajectory type and rung on the trajectory; (3) a scaling law holds for decays from one trajectory to another. An interesting result of this law, which is independent of the barrier factor, is that the decay $N_2\mathrm{}\left(1688\right)\mathrm{}\to {\Delta }_1\mathrm{}\left(1238\right)\mathrm{}\pi$ is strongly inhibited relative to other $p$-wave decays. In the Appendix a simple derivation is given of the most general expression for the decay of an arbitrary-spin baryon into a spin-$\frac{3}{2}$ final baryon and a spin-zero meson.