Fine structure excitation transfer between the potassium 42P states induced by collisions with caesium atoms

Applying diode-laser resonant fluorescence method, the cross sections for the excitation energy transfer of the collisional process K*(4² P _1/2)+Cs(6² S _1/2)?K*(4² P _3/2)+Cs(6² S _1/2) have been measured. The values we have obtained are σ(1/2→3/2)=77 Ų and σ(3/2→1/2)=48 Ų. These results complete the sequence of data for the fine-structure mixing of the first-resonance states of alkali atoms colliding with the ground-state caesium atoms.