  We study the dynamics of atoms in optical traps when exposed to laser cooling
light that induces light-assisted collisions. We experimentally prepare
individual atom pairs and observe their evolution. Due to the simplicity of the
system (just two atoms in a microtrap) we can directly simulate the pair's
dynamics, thereby revealing detailed insight into it. We find that often only
one of the collision partners gets expelled, similar to when using blue detuned
light for inducing the collisions. This enhances schemes for using
light-assisted collisions to prepare individual atoms and affects other
applications as well.
