It is shown that in gauge-field models for the electromagnetic and weak hadronic currents, restrictions are imposed on the way the symmetry is broken if the algebra of currents is to hold. A modified form of Weinberg's second sum rule is proposed, and relations among vector-meson masses are obtained on the assumption of nonet symmetry for the currents.

• Received 20 May 1968

DOI:https://doi.org/10.1103/PhysRevLett.21.177