Eur. Phys. J. Special Topics 169, 29-34 (2009)
https://doi.org/10.1140/epjst/e2009-00969-8

Photon polarization in the two-photon decay of heavy hydrogen-like ions

¹ Physikalisches Institut, Universität Heidelberg, 69120 Heidelberg, Germany
² Institut für Physik, Universität Kassel, 34132 Kassel, Germany
³ Laboratoire Kastler Brossel, École Normale Supérieure, CNRS et Université, Pierre et Marie Curie-Paris 6, Case 74, 4 place Jussieu, 75005 Paris, France
⁴ Gesellschaft für Schwerionenforschung (GSI), 64291 Darmstadt, Germany
⁵ Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany

Corresponding author: surz@physi.uni-heidelberg.de

Abstract

We have applied the density matrix and second-order perturbation theory in order to re-analyze the two-photon decay of hydrogen-like ions for the polarization of emitted light. Special attention is paid to the linear polarization of one of the photons, while the spin state of the second photon is supposed to be unobserved. For such an “angle-polarization” correlation of the two photons we investigate the contributions that arise from non electric-dipole terms in the expansion of the electron-photon interaction. Detailed calculations are performed for the 2s_1/2 →1s_1/2 and 3d_5/2 →1s_1/2 transitions in neutral hydrogen as well as in hydrogen-like uranium.