Figure 1

${\mathrm{H}}_2$ photodouble ionization cross sections computed using time-dependent (TDCC) [6] and time-independent (ECS) [5] close coupling as a function of the orientation ${\theta }_2$ of the momentum direction ${\mathbf{k}}_2$ of one electron relative to a laboratory $z_L$ axis along the polarization direction $\widehat{ϵ}$ for 25 eV electron pairs with equal energy sharing. In each plot, the momentum direction ${\mathbf{k}}_1$ of the other electron is aligned along a $y_L$ axis perpendicular to the ${\mathbf{k}}_2$, $\widehat{ϵ}$ plane. The three plots (a), (b), and (c) thus show three orientations ${\theta }_N$, ${\varphi }_N$ of the ion-pair direction ${\mathbf{K}}_{-}$ along the three axes $y_L$, $x_L$, and $z_L$, respectively. The polar-plot insets show a folded comparison with the experimental measurements of Gisselbrecht et al. [3].Reuse & Permissions

Figure 2

Rotating ${\mathbf{k}}_1$, ${\mathbf{k}}_2$ plane of an ejected electron pair following the photofragmentation of molecular hydrogen. Here ${\mathbf{k}}_{+}={\mathbf{k}}_1+{\mathbf{k}}_2$ and ${\mathbf{k}}_{-}=({\mathbf{k}}_1-{\mathbf{k}}_2)/2$ refer to the electron pair and ${\mathbf{K}}_{-}=({\mathbf{K}}_1-{\mathbf{K}}_2)/2$ to the ion pair. The top three insets illustrate the three frames of reference used in the text. Left to right: Laboratory, molecular, and electron-pair.Reuse & Permissions

Figure 3

Fits (solid curves) using Eq. (8) and thus a three-state superposition ${}^{1}P_{\lambda =1}+{}^{1}D_{\lambda =1}+{}^{1}F_{\lambda =1}$ from Eq. (7) to the ${\mathrm{H}}_2$ photodouble ionization cross sections in Figs. 1b, 1c. The dashed curves show the TDCC result from Fig. 1.Reuse & Permissions

Figure 4

An electron-pair angular distribution for fixed ${\widehat{\mathbf{k}}}_1·{\widehat{\mathbf{k}}}_2$ looking down a $z_L$ axis along $\widehat{ϵ}$ onto the ${\widehat{\mathbf{x}}}_L={\widehat{\mathbf{K}}}_{-}$, ${\widehat{\mathbf{y}}}_L$ plane as a function of the azimuthal orientation ${\varphi }_2$ of the pair. Here ${\mathbf{k}}_2$ and ${\mathbf{k}}_1$ are oriented above and below, respectively, the ${\widehat{\mathbf{K}}}_{-}$, ${\widehat{\mathbf{y}}}_L$ plane (cf. 3D inset) with fixed polar angles ${\theta }_2=\pi /4$ and ${\theta }_1=\pi -{\theta }_2$ while varying ${\varphi }_2$ along with ${\varphi }_1={\varphi }_2+\pi /2$. The solid four-lobe curve is the resulting ${cos}^{2}2{\varphi }_2$ distribution predicted from the axial-vector contributions to Eq. (7), arbitrarily scaled to a TDCC calculation shown with the dashed curve. The circle radius equals $0.03\mathrm{b}/{\mathrm{sr}}^2\mathrm{eV}$.Reuse & Permissions