Dissociation dynamics of the CO$_{\mathrm{2}}$ molecule studied with XUV pump and near-infrared probe experiments*

Ultrafast dynamics of ionic states of the CO$_{\mathrm{2}}$ molecule have recently been studied by employing a pump-probe technique using broadband ultrashort XUV-pump pulses containing the 11$^{\mathrm{th}}$ to 17$^{\mathrm{th}}$ harmonics of a near-infrared laser (NIR) [1]. Here, we present the results of a complimentary experiment employing longer (\textasciitilde 100 fs) but narrowband, single harmonic (11$^{\mathrm{th}}$ or 13$^{\mathrm{th}})$ pulses to excite molecular wave packets to specific states of CO$_{\mathrm{2}}^{\mathrm{+}}$, which are probed by NIR-induced dissociation. We employ a reaction microscope to measure energy- and angle-resolved yields of all charged reaction fragments as a function of XUV-NIR delay. In particular, the delay dependence of O$^{\mathrm{+}}$ and CO$^{\mathrm{+}}$ ion production for parallel and perpendicular NIR and XUV polarizations are contrasted with the data obtained by Timmers \textit{et al.} [1] using ultrashort broadband train of harmonics. [1] H. Timmers \textit{et al.}, Phys. Rev. Lett. \textbf{113}, 113003 (2004).