Mass parameters for collective variables of a dinuclear system and strongly
deformed mononucleus are microscopically formulated with the linear response
theory making use of the width of single particle states and the
fluctuation-dissipation theorem. For the relative motion of the nuclei and for
the degree of freedom describing the neck between the nuclei, we calculate mass
parameters with basis states of the adiabatic and diabatic two-center shell
model. Microscopical mass parameters are found larger than the ones obtained
with the hydrodynamical model and give a strong hindrance for a melting of the
dinuclear system along the internuclear distance into a compound system.
Therefore, the dinuclear system lives a long time enough comparable to the
reaction time for fusion by nucleon transfer. Consequences of this effect for
the complete fusion process are discussed.Comment: 22 pages, 7 figures, submitted to Nucl.Phys.
