Origin of magnetic dichroism in angular-resolved photoemission from ferromagnets

It is shown that recently discovered effects of magnetic x-ray dichroism in angular-resolved photoemission from core levels of ferromagnets appear due to the spin-orbit and exchange splitting of core levels. The effects are proportional to the state multipoles characterizing the alignment and orientation of the hole levels, and can be observed with circularly polarized, linearly polarized, and unpolarized light. Possible applications of these effects in investigations of magnetic structures and adsorbates are pointed out.