The mixing ratios of $M1$ and $E2$ radiation for transitions in ${}^{11}\mathrm{B}$ have been determined by measuring the azimuthal asymmetry of the radiation emitted from levels populated by resonant absorption of polarized photons. The photon-scattering experiments were carried out at the Free-Electron Laser Laboratory at Duke University using nearly monoenergetic and linearly polarized photon beams. The mixing ratios were deduced from a comparison of the measured azimuthal asymmetries with calculations for the angular distributions of mixed transitions.

• Received 14 July 2008

DOI:https://doi.org/10.1103/PhysRevC.79.047601