Coherent-state multipole moments: Source of important scattering information

Coherent states are completely parametrized in terms of multipole moments and their time derivatives. For hydrogen atoms excited by electron impact, our calculations show that these parameters provide new information concerning the final-state interactions of the hydrogen atom and the projectile electron. These large final-state-interaction effects make first-order perturbation calculations inappropriate. We present calculations which properly incorporate these dynamical effects. Experiments which determine these parameters are discussed.