title: Quantum-state resolved bimolecular collisions of velocity-controlled OH with NO radicals.
abstract: Whereas atom-molecule collisions have been studied with complete quantum-state resolution, interactions between two state-selected molecules have proven much harder to probe. Here, we report the measurement of state-resolved inelastic scattering cross sections for collisions between two open-shell molecules that are both prepared in a single quantum state. Stark-decelerated hydroxyl (OH) radicals were scattered with hexapole-focused nitric oxide (NO) radicals in a crossed-beam configuration. Rotationally and spin-orbit inelastic scattering cross sections were measured on an absolute scale for collision energies between 70 and 300 cm(-1). These cross sections show fair agreement with quantum coupled-channels calculations using a set of coupled model potential energy surfaces based on ab initio calculations for the long-range nonadiabatic interactions and a simplistic short-range interaction. This comparison reveals the crucial role of electrostatic forces in complex molecular collision processes.
authors.affiliation: Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany.
authors.forename: Moritz
authors.initials: M
authors.lastname: Kirste
authors.forename: Xingan
authors.initials: X
authors.lastname: Wang
authors.forename: H Christian
authors.initials: HC
authors.lastname: Schewe
authors.forename: Gerard
authors.initials: G
authors.lastname: Meijer
authors.forename: Kopin
authors.initials: K
authors.lastname: Liu
authors.forename: Ad
authors.initials: A
authors.lastname: van der Avoird
authors.forename: Liesbeth M C
authors.initials: LM
authors.lastname: Janssen
authors.forename: Koos B
authors.initials: KB
authors.lastname: Gubbels
authors.forename: Gerrit C
authors.initials: GC
authors.lastname: Groenenboom
authors.forename: Sebastiaan Y T
authors.initials: SY
authors.lastname: van de Meerakker
mesh_terms: D017665:Hydroxyl Radical / Q000737:chemistry*; D009569:Nitric Oxide / Q000737:chemistry*; D011789:Quantum Theory; D055672:Static Electricity
chemical_list: D009569:Nitric Oxide; D017665:Hydroxyl Radical