$F$ and $D$ couplings of baryons and mesons are shown to arise naturally with a simple extension of the gauge formalism to a ${(\mathrm{S}{\mathrm{U}}_3\times \mathrm{S}{\mathrm{U}}_3)}_L\times {(\mathrm{S}{\mathrm{U}}_3\times \mathrm{S}{\mathrm{U}}_3)}_R$ group structure. In its general formulation the theory needs parity doubltets of (0+) and (0-) ninefolds. It admits of (two types of $F$ and $D$ coupled) (1+) and (1-) vector and axial-vector meson multiplets, a specially attractive combination of currents which emerges from the formalism being an equal mixture of vector $F$ with axial-vector $D$ [the case of ${\left(\mathrm{S}{\mathrm{U}}_3\right)}_L\times {\left(\mathrm{S}{\mathrm{U}}_3\right)}_R$]. The theory also admits an approximate (Bronzan-Low) type of quantum number.

• Received 18 June 1964

DOI:https://doi.org/10.1103/PhysRev.136.B763