Electromagnetic Corrections to Isotopic Spin Conservation

Abstract

If electromagnetic interactions are wholly responsible for all departures from isotopic spin invariance, then the strict conservation law $\Delta T=0\mathrm{}$ may be replaced, to order $e^2$, by the rule $\left|\Delta T\right|<~2$. Consequences of this weaker restriction are discussed for elementary particle masses, scattering processes, and weak-inter-action decay processes. The apparent absence in nature of particles with isotopic spins greater than one makes it difficult to find very practical experimental tests of this rule.