The weak contributions to the anomalous magnetic moment of the muon are calculated in a proposed theory of the weak and electromagnetic interactions. The result is finite and of order $\Delta g_{\mu }\approx {10}^{-8\mathrm{}}$, too small to be measured at present. The present agreement between theoretical and experimental values of the muon magnetic moment does not even rule out the possibility that the scalar meson required by this theory has a very small mass. If this mass were sufficiently small, then the scalar-meson field would produce shifts of the order of a hundred parts per million in muonic-atom energy levels.

• Received 22 November 1971

DOI:https://doi.org/10.1103/PhysRevD.5.2396