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 B-2(2) resonance. We focus on the H- anion fragment, which is produced via dynamics passing through and avoiding the conical intersection with the lower A(1) state, leading to OH ((2)Pi) and OH ((2)Sigma), 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.