SIGNATURES OF MULTIPHONON AND NEUTRON TRANSFER COUPLINGS IN THE FUSION OF S-36,S-32-110(PD)

Fusion-evaporation cross sections have been measured for S-32,S-36+Pd- 110 to high accuracy in the energy range around the Coulomb barrier. T he two extracted fusion barrier distributions display very similar str uctures with two well-resolved peaks below the nominal barrier, which are consistent with a model calculation including the coupling of the one-, two-, and three-phonon collective vibrations of Pd-110. A third lower-energy barrier, together with a strong relative cross section en hancement, is observed for S-32+Pd-110 and is reproduced by coupling t he two-neutron pickup channel which has a large and positive ground st ate Q value (+5.1 MeV). For S-36+Pd-110, the calculated effect of the corresponding transfer channel (with negative Q value) is much smaller .