Evaporation residue excitation functions and o.-multiplicities from complete fusion of 0 with Au and Pb have been measured &om the fusion threshold up to 140 MeV incident energy. The data allow the conclusion that strongly overdamped motion cannot be dominant at energies in the vicinity of the fusion barrier below E' 50 MeV. At excitation energies above 50 MeV the residue cross section for 0 + Pb is much greater than predicted kom the statistical model with conventional parametrizations. The enhancement is not explained by incorporating dynamical effects into the analysis. An alternative suggestion based on deexcitation-chain dependent Sssion barriers is discussed. PACS number(s): 25.70.Gh, 25.70. Jj

No abstract

High-energy photon yields from the reactions ' C + ' ' Sn at 10 MeV/nucleon have been measured. The ratio of cross sections (E~& 30 MeV) o (' Sn)/o (" Sn) is 1.6 6 0.2, which is larger than expected within the equal-participant model. The elementary n-p-p cross section is evaluated within the neutral scalar 0 meson exchange model, and implemented into a BUU code. The results of the BUU calculation suggest that the high-energy p-ray yield differences for the two Sn isotopes arise from the differences in nucleon phase-space distributions. The sensitivity of the high-energy photon production to the initial phase-space conditions is explored.PACS number(s): 25.70.z

No abstract