Ultrafast dynamics in photoionized CO$_{\mathrm{2}}$ studied by XUV-IR pump-probe experiments*

$^{\mathrm{1}}$James R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, KS, USA We present the results of a pump-probe experiment studying ultrafast dynamics of photo-ionized CO$_{\mathrm{2}}$ using a combination of broadband XUV pulses and near-infrared (NIR) pulses, \textasciitilde 25 fs duration. The multi-harmonics pulse, which contains the 11$^{\mathrm{th}}$ to 45$^{\mathrm{th}}$ harmonics of a 790 nm NIR laser, is used to excite molecular wave packets in CO$_{\mathrm{2}}^{\mathrm{+}}$, which are then probed by near-infrared-induced dissociation. We use a velocity map imaging setup to measure the yields and angle-resolved kinetic energy distributions of all charged fragments as a function of XUV-NIR delay. The delay dependence of O$^{\mathrm{+}}$ and CO$^{\mathrm{+}}$ ion production for parallel and perpendicular NIR and XUV polarizations, are compared to the data reported in [1] for a shorter harmonics train, and to data obtained using narrow-band isolated harmonic (11$^{\mathrm{th}}$ or 13$^{\mathrm{th}})$ as a pump. [1] H. Timmers et al, Phys. Rev. Lett. 113, 113003 (2014).