Fusion near and below the barrier for the systemsS32,34+Mg24,25,26andS32+Al27

Excitation functions are reported for total fusion near and below the Coulomb barrier of the systems ${}_{}{}^{32,34}{}_{}{}^{}\mathrm{S}$+${}_{}{}^{24,25,26}{}_{}{}^{}\mathrm{Mg}$ and ${}_{}{}^{27}{}_{}{}^{}\mathrm{Al}$. The data cannot be reproduced by one-dimensional barrier penetration calculations. The enhancement of the cross sections at low energies is compared to predictions of models taking into acount the static deformation or zero point vibration of the reaction partners. Calculations including zero point motion do not reproduce the observed variations of the measured cross sections with respect to the neutron number of target and projectile. Reasonable agreement is obtained when calculating fusion between statically deformed nuclei. Finally, the fusion process is described in a quantum mechanical coupled channels model, indicating the importance of dynamical effect on sub-barrier fusion.