Electron Scattering, Isospin Mixing, and the Structure of the 12.71- and 15.11-MeV Levels inC12

Abstract
The structure and the degree of isospin mixing for the 1+ levels in C12 at 12.71 MeV (T=0) and 15.11 MeV (T=1) are determined from measured 180°-electron-scattering form factors. The resulting charge-dependent isospin-mixing matrix element ranges from 130 to 165 keV depending on the theoretical model of the isoscalar form factor.