Two-photon transition rates are important in determining astrophysical quantities such as population balance in planetary nebulae. Our group recently calculated two-photon decay rates in heliumlike ions including the finite nuclear mass effects . We have now perturbatively added relativistic corrections to these results, giving the most precise and accurate calculations to date for these transitions. In the process of calculating the two-electron Breit matrix elements, we first tested the derived two-photon, two-electron decay (2nd order field +1st order relativistic) perturbation equation on the equivalent one-electron process which obeys the same formula. In this process, we derived (and will report on) one-electron Breit-Pauli operators that were shown to be equivalent to the corresponding Dirac operators. A continuous gauge parameter is considered, and the operators are compared to the long-wavelength QED operators derived for few-electron atoms by Pachucki .
 Bondy, Aaron T., Donald C. Morton, and G. W. F. Drake. "Two-photon decay rates in heliumlike ions: Finite-nuclear-mass effects." Physical Review A 102.5 (2020): 052807
 Pachucki, Krzysztof. "Long-wavelength quantum electrodynamics." Physical Review A 69.5 (2004): 052502.
Funding from NSERC and QE-II is gratefully acknowledged.
|Presenter name||Aaron T. Bondy|
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