  We study the interaction between a moving three-level lambda rubidium atom
and a single mode cavity field in the presence of Kerr-like medium. We derive
the basic equations of motion for atomic system and show that it is exactly
solvable in the rotating wave approximation (RWA). The momentum increment, the
momentum diffusion and the Mandel Q parameter of this system are studied. We
investigate numerically the influence of Kerr-Like medium on the evolution of
the previous statistical properties in the exact resonate and nonresonate case
where the atom is initially prepared in a momentum eigenstate and the field in
the squeezed state. It is found that the Kerr medium has an important effect on
their evolution. Finally, conclusion and discussion are given.
