Hanle effect in coherent backscattering
  We study the shape of the coherent backscattering (CBS) cone obtained when resonant light illuminates a thick cloud of laser-cooled rubidium atoms in presence of a homogenous magnetic field. We observe new magnetic field-dependent anisotropies in the CBS signal. We show that the observed behavior is due to the modification of the atomic radiation pattern by the magnetic field (Hanle effect in the excited state). 
G. Labeyrie (1), C. Miniatura (1), C. A. Mueller (1), O. Sigwarth (2),   D. Delande (2) and R. Kaiser (1) ((1) Laboratoire O...