High-precision electron scattering measurements from the 15.109-MeV $1^{+}$ state in ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ are made at $\theta =75\mathrm{} \mathrm{and} 110°$ with $35\le E\le 55$ MeV. From the measurements $B\left(M1\mathrm{}\right)\mathrm{}$ is extrapolated to the photon point and the radiative width is determined, ${\Gamma }_{\gamma }=37.0\mathrm{}\pm 1.1$ eV. The corresponding weak magnetism results for $\beta$ decay and $\mu$ capture are given.

• Received 27 December 1972

DOI:https://doi.org/10.1103/PhysRevC.8.23