The Theory of Atomic Collisions

D. V. Skobelʹt︠s︡yn

Bo Gao

A general theory of slow-atom collisions is presented with special emphasis on the effects of nuclear statistics and atomic fine and/or hyperfine structures. Symmetry properties of the collision complex and correlations between the molecular states and the separated-atom states are carefully examined. The frame transformations between various angular momentum coupling schemes are derived, which, in combination with the multichannel quantum defect theory, provides a solid foundation for the computation and the physical interpretation of slow-atom collision processes. The theory reduces to those of Stoof et al. [Phys. Rev. B 38, 4688 (1988)] and Zygelman et al. [Phys. Rev. A 49, 2587 (1994); 50, 3920 (1994)] in their respective ranges of validity. \textcopyright{} 1996 The American Physical Society.

Jeremy M. Hutson

Kalle‐Antti Suominen

I describe the current theories for cold collisions between laser-cooled and trapped neutral atoms in light fields. The emphasis is on the dynamical nature of the problem, i.e. on the collisional loss of atoms from the trap or collisional heating of the atomic cloud. The recent work on optical shielding of collisions is also reviewed.

Joachim Burgdörfer

Sergei I Yakovlenko

A theory is given of radiative collisions, i.e., of elementary events in which the emission of a photon occurs in the course of a collision. Special attention is paid to radiative collisions stimulated by a laser field. Simple but clear approaches formulated in the forties or fifties are described briefly. This theory applies, in particular, to collisions in a strong electromagnetic field which affect the collision dynamics. Chemical radiative collisions, i.e., chemical reactions stimulated by photons absorbed in the course of a collision, are reviewed. An analysis is made of several recent experiments in which the theoretically predicted effects were observed: these include the radiative-collisional transfer of excitation from atom to atom, nonlinear effects due to the influence of the field on the collision dynamics, and photosubstitution of one of the atoms in a halogen molecule with an inert gas atom.