Quark Model for Baryon-Baryon Processes

A quark ($Q$) model recently proposed by the authors for high-energy meson-baryon and photoproduction processes is extended to high-energy baryon-baryon scattering and production of negative-parity baryons. The positive- and negative-parity baryons are assumed to belong, respectively, to the representations (56,1) and (70,3) of the group $\mathrm{SU}\left(6\right)\mathrm{}\times O\left(3\right)\mathrm{}$. Sum rules resembling those of $\mathrm{SU}\left(3\right)\mathrm{}$ and $\mathrm{SU}(6,6)\mathrm{}$, but differing in details, are obtained for the baryon-baryon processes within the 56 representation. An interesting sum rule which is obtained for negative-parity baryon production involves only nonstrange particles and could be within fairly early reach of experiment. The model is primarily characterized by an impluse approximation for $Q-Q$ scattering and thus disallows processes involving exchanges of more than one unit of charge, hypercharge, and even spatial symmetry, among the initial and final $3Q$ states representing the baryons. This last condition precludes the high-energy peripheral production of metastable baryon states like the Roper resonance, which we believe to have an internal orbital structure of $L^P=1^{+}$.