Kinetic Supermultiplets ofŨ(12). II

Abstract

Possible baryon "kinetic supermultiplets" are discussed as candidates for classifying higher baryonic resonances of negative parity. The "kinetic supermultiplets" had been proposed, in a previous work, as an extension of the supermultiplet scheme of broken $\tilde{U}\mathrm{}\left(12\right)\mathrm{}$. The classification of higher boson resonances in terms of a "kinetic supermultiplet" has proved remarkably successful and led to correct predictions of quantum numbers and accurately verified mass relations. The baryon "kinetic supermultiplet" discussed here employs the hitherto unused representation 220 in $\tilde{U}\mathrm{}\left(12\right)\mathrm{}$, which corresponds to the 20 of ${\mathrm{SU}}_6$, and is tentatively chosen on the basis of its economy. It groups together a baryon nonet with $J^P={\frac{1}{2}}^{-}$, another nonet with $J^P={\frac{3}{2}}^{-}$, and a singlet with $J^P={\frac{5}{2}}^{-}$. The mass formulas are derived up to first order in ${\mathrm{SU}}_3$ breaking. Based on the quantum-number predictions and the mass formulas, we attempt a classification of higher baryon resonances, and present a tentative scheme of assignments and consequent predictions. An alternative scheme employing the representation 364 in $\tilde{U}\mathrm{}\left(12\right)\mathrm{}$, corresponding to the 56 of ${\mathrm{SU}}_6$ is also examined.