Particle order: A new fundamental concept in Hadron physics

Abstract

The sequentially ordered SM, and the DTU scheme based on it, were seen to describe from a unified point of view a wide range of phenomena in the meson sector; indeed, it appears to have the potential of becoming a quantitative theory of mesons (of course a strong-interaction theory cannot be complete without including all hadrons, but to the extent that baryons do not affect the calculations too strongly, it appears to be a good approximation for mesons). Given this state of affairs, we found it hard to believe that the ordered SM idea would remain limited to mesons, particularly since baryons, too, exhibit features that we had come to recognize as the hallmark of the ordered SM, such as quark structure (qqq), the OZ[ rule (e.g., ~--~ p/~ etc. is strongly suppressed), Regge pole dominance, exchange degeneracy for many trajectories, etc. In fact, the need to extend duality and particularly the DTU program to baryons had been felt acutely for quite a while, and had given rise to numerous attempts to accomplish this, none of them really successful. One of the more persistent obstacles was the problem posed by the