Superconvergence relations are known to obey algebraic equations involving the spin and the mass. States of the same helicity fall into reducible representations of $\mathrm{SU}\left(2\right)\mathrm{}\otimes \mathrm{SU}\left(2\right)\mathrm{}$. When the helicity is ±½, the two representations are related both by parity operation and by spin raising or lowering operators in the helicity space. The combination of the two yields sufficient constraints to solve for a number of properties of low-lying resonances, with results in good agreement with experiment.

• Received 6 April 1970

DOI:https://doi.org/10.1103/PhysRevD.2.357