Fully differential single-photon double ionization of neon and argon*

Double photoionization of neon and argon differ significantly from helium in that three different final state couplings of the residual double ion ($^1S$, $^1D$, and $^3P$) are possible and greatly impact the observed angular distributions, but the multi-electron nature of such targets makes \emph{ab initio} theoretical treatments of this correlated process a challenge. Triply differential cross sections (TDCS) have been calculated for single photon double ionization of these heavier rare gases at various photon energies by utilizing an expanded frozen-core treatment to represent the remaining $N-2$ target electrons of the residual ion. The resulting angular distributions are compared with and show significant agreement with existing experimental data.