Title: Impact of Cavity on Molecular Ionization Spectra

Abstract: Ionization phenomena are widely studied for decades. With the advent of cavity technology, the question arises how the presence of quantum light affects the ionization of molecules. As the ionization spectrum is recorded from the ground state of the neutral molecule, it is usually possible to choose cavities which do not change the ground state of the target, but can have a significant impact on the ion and the ionization spectrum. Particularly interesting are cases where the produced ion exhibits conical intersections between its close-lying electronic states which is known to give rise to substantial nonadiabatic effects. We demonstrate by an explicit realistic example that vibrational modes not relevant in the absence of the cavity do play a decisive role when the molecule is in the cavity. In this example, dynamical symmetry breaking is responsible for the coupling between the ion and the cavity and the high spatial symmetry enables a control of their activity via the molecular orientation relative to the cavity field polarization. Significant impact on the spectrum by the cavity is found and shown to even substantially increase when less symmetric molecules are considered.