Two-center interference in p–H₂ electron-transfer collisions

We report on measurements of transfer excitation in collisions of 0.3-1.3 MeV protons with spatially oriented H₂ molecules. Evidences of two center interference are found in the angular distribution of the molecule after a transfer excitation process and directly in the projectile angular scattering distributions. These features can be explained in a way which is analogous to that for the interferences in Young's classical double slit experiment: The fast projectiles preferentially capture electrons close to either of the molecular nuclei, and thereby they change their momenta and de Broglie wavelengths. The waves emerging from the two 'slits' of the molecule interfere yielding the observed interference structure.