Effects of diabaticity on fusion of heavy nuclei in the dinuclear model ...

3-2: Diabatic contribution ∆Vdiab as a function <strong>of</strong> elongation λ for the system Figure 100Mo+ Mo (solid line). The neutron and proton diabatic contributions are shown by dotted and
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dashed lines, respectively. The nuclei are considered spherical with ε =0.74.
phenomenological double folding potential [65]. A discrepancy with the adiabatic potential is
seen for small elongations where the phenomenological potential is more repulsive than the
diabatic one. The discrepancy becomes smaller if we take into account a decrease <strong>of</strong> ε with
decreasing elongation. This is demonstrated for the system 110 Pd+ 110 Pd in Fig. 3-6, where the
diabatic potential is shown as a function <strong>of</strong> ε for constant values <strong>of</strong> λ. The minimum <strong>of</strong> the
diabatic potential moves to smaller values <strong>of</strong> ε with decreasing values <strong>of</strong> λ (or R).
Fig. 3-6 shows diabatic potentials for the systems 96 Zr+ 96 Zr and 90 Zr+ 90 Zr as a function <strong>of</strong>
ε for λ =1.54 near to the minimum <strong>of</strong> the pocket in λ. The diabatic contribution is smaller as
a function <strong>of</strong> ε for the 96 Zr+ 96 Zr system than for the 90 Zr+ 90 Zr system (lower part <strong>of</strong> Fig. 3-7).
The reason for this can be seen through an analysis <strong>of</strong> the single particle spectra (Fig. 3-8).
In the case <strong>of</strong> 90 Zr+ 90 Zr, more diabatic levels with larger slopes cross the Fermi-level at larger
values <strong>of</strong> ε. From Figs. 3-3 and 3-8 it follows that the diabatic contributions are larger with
respect to the relative coordinate than with respect to the neck coordinate. This is explained by
the number <strong>of</strong> crossings <strong>of</strong> diabatic states in the variation <strong>of</strong> both coordinates. In most systems
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