Publisher's Note: Molecular oxygen observed by direct photoproduction from carbon dioxide [Phys. Rev. A 95, 011404(R) (2017)]

Figure 1

(a) Measured time-of-flight spectrum of photoions. (b) and (c) present measured photoion-photoion coincidence distributions without and with selection conditions for the two fragmentation channels, respectively. (d) and (e) illustrate momentum correlation distributions for the ${\text{C}}^{+}+{\text{O}}_2{}^{+}$ channel along the laser polarization direction between ${\text{C}}^{+}$ and ${\text{O}}_2{}^{+}$ ions before and after applying the coincidence selection, respectively. The two-body coincidence selection conditions include momentum conservation conditions of $|p_{x1}+p_{x2}|<2\text{a.u.}$ and $|p_{y1}+p_{y2}|<5\text{a.u.}$, and a further condition of $\sqrt{p_{x1}^2+p_{y1}^2}>30\text{a.u.}$ for the ${\text{C}}^{+}+{\text{O}}_2{}^{+}$ channel to get rid of overlapping with other signals, where the $x$ and $y$ directions are defined along the gas jet and the laser propagation direction, and the indexes 1 and 2 indicate the first and the second considering particles, respectively. These coincidence conditions, together with the momentum conservation condition along the $z$ direction $\left(|p_{z1}+p_{z2}|<3\text{a.u.}\right)$, are applied in the data analysis for further studies.