Towards disentangling coupled electronic-vibrational dynamics in ultrafastnon-adiabatic processes

Femtosecond time-resolved photoelectron spectroscopy is emerging as a new t echnique for investigating polyatomic excited state dynamics. Due to the se nsitivity of photoelectron spectroscopy to both electronic configurations a nd vibrational dynamics, it is well suited to the study of non-adiabatic pr ocesses such as internal conversion, which often occur on sub-picosecond ti me scales. We discuss the technical requirements for such experiments, incl uding lasers systems, energy- and angle-resolved photoelectron spectrometer s and new detectors for coincidence experiments. We present a few examples of these methods applied to problems in diatomic wavepacket dynamics and ul trafast non-adiabatic processes in polyatomic molecules.