SYMMETRY-BREAKING IN PHOTON-INDUCED A1 LVV AUGER DECAYS

The angular distributions of Si K-alpha-excited Al 1s photoemission, the L2,3VV Auger line, and its 15-eV high-energy satellite (L*VV), are measured over the hemisphere above the Al(001) surface, with an experimental geometry such that the incident radiation breaks the mirror symmetries associated with (100) and (110) crystal planes. Strong photon-polarization effects are seen in 1s photoemission, and are also reproduced by single-scattering calculations. A symmetry analysis indicates that in the high-energy satellite the photon-induced mirror-symmetry breaking persists. A comparison with single-scattering calculations shows that the LVV and the L*VV decays produce Auger electrons with different angular-momentum character.