Highly anisotropic resonant dynamics in the aligned-aligned scattering of cold diatoms

The dynamics of a resonant oriented scattering process dominated by a single partial wave provide the most sensitive probe of the long-range anisotropic forces important to chemical reactions. Here, we control the collision temperature and geometry to probe the dynamics of the cold (<2 K) rotationally inelastic scattering of a pair of optically state-prepared D2 molecules. The collision temperature is manipulated by combining the strobing action of laser state preparation and detection with the velocity dispersion of the molecular beam. When the bond axes are aligned parallel to the collision velocity, the scattering rate drops by nearly an order of magnitude when collision energies >1 K are removed, demonstrating a clear geometry-dependent resonance. Using partial wave analysis of the measured scattering angular distribution, we determine that an l = 2 shape resonance originates from the collisions between a pair of aligned D2 molecules. Our experiment illustrates the strong anisotropy of the long-range quadrupole-quadrupole interaction that controls the dynamic resonance for diatom-diatom collisions.

Rotationally inelastic scattering of O3–Ar: state-to-state rates with the multiconfigurational time dependent Hartree method

The rates of state-changing collisions are compared for different isotopologues of ozone from quantum scattering calculations with the MCTDH method.

Imaging inelastic scattering of CO with argon: polarization dependent differential cross sections

Rotationally inelastic scattering of carbon monoxide (CO) with argon at a collision energy of 700 cm−1 has been investigated by measuring polarization dependent differential scattering cross sections (PDDCSs) for rotationally excited CO molecules using a crossed molecular beam apparatus coupled with velocity-map ion imaging.

Inelastic scattering dynamics of ortho and para hydronium ions, o-H3O+ and p-H3O+, with He at low temperature

In this work, we investigated rotationally inelastic scattering of both hydronium ion forms, p-H3O+ and o-H3O+, colliding with a helium atom.