Nonadiabatic transition probabilities in the presence of strong dissipation

Strong dissipative effects on the nonadiabatic transition for the two level system are studied. We focus on a strong dissipation for the diabatic states, and derive the exact transition probability making use of the effective master equation. We consider the case where the external field is swept from not only a negative large value but also from the resonant field, and the exact transition probabilities in these cases are derived.