A new type of interference phenomenon in cold collisions of electrons with N_2

摘要

A novel cold collision phenomenon is described which is caused by interference within the manifold of electron waves of unit angular momentum (p-waves). Experimental electron scattering data in N_2, down to energies of 10 meV, reveal this phenomenon through the angular distribution of scattered electrons. Ab initio theory, analytical results and a simple physical model illustrate how interference arises through the presence of a quadrupole on the target N_2. The effect is of a general nature and may be found in all systems in which, in the cold regime, charged particles interact with target species with a permanent quadrupole moment.