Low-q2 electron scattering from the 15.109-MeV state of 12C and the conserved-vector-current test

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