ROLE OF MASS RENORMALIZATION IN ADIABATIC QUANTUM TUNNELING

We introduce an adiabatic expansion to derive a formula for a macrosco pic quantum tunneling probability that takes the mass renormalization due to the coupling to fast environmental degrees of freedom into acco unt. The formula is applied to studying the effects of nuclear vibrati onal excitations on the fusion cross section in heavy-ion collisions a t energies below the Coulomb barrier. It is shown that mass renormaliz ation plays an important and useful role to discuss the effects of vib rational excitations of moderate energy. Also a general proof is given to show that the renormalized part of the effective mass appearing in our formula is the cranking mass.