Interelectronic-interaction effects on the two-photon decay rates of   heavy He-like ions
  Based on a rigorous QED approach a theoretical analysis is performed for the two-photon transitions in heavy He-like ions. Special attention is paid to the interelectronic-interaction corrections to the decay rates that are taken into account within the two-time Green-function method. Detailed calculations are carried out for the two-photon transitions 2^1S_0 -> 1^1S_0 and 2^3S_1 -> 1^1S_0 in He-like ions within the range of nuclear numbers Z=28-92. The total decay rates together with the spectral distributions are given. The obtained results are compared with experimental values and previous calculations. 
A. V. Volotka, A. Surzhykov, V. M. Shabaev, G. Plunien
physics.atom-ph