Observation of the dynamics leading to a conical intersection in dissociative electron attachment to water

Following prior work on the lower-energy resonances, we apply techniques of momentum imaging and ab initio scattering calculations to the process of dissociative electron attachment to water via the highest-energy ²B₂ resonance. We focus on the H^- anion fragment, which is produced via dynamics passing through and avoiding the conical intersection with the lower A₁ state, leading to OH (²Π) and OH (²Σ), respectively. The momentum imaging technique, when combined with theoretical calculations on the attachment amplitude and dissociation dynamics, demonstrates that the angular distributions provide a signature of the location of the conical intersection in the space of nuclear configurations.