Effect of the entrance channel mass asymmetry on the limitation of light heavy-ion fusion cross sections

Evaporation residues resulting from the 11B+27Al and 19F+19F fusion reactions leading to the 38Ar compound nucleus and from the 19F+(12C, 16O, 27Al, 40Ca) reactions have been measured at incident energies 32 MeV≤EL(19F)≤72 MeV and 15 MeV≤EL(11B)≤50 MeV. The hindrance of the fusion cross sections, at energies above the interaction barrier, show a clear dependence on the entrance channel mass asymmetry. This dependence is discussed in terms of model predictions that treat explicitly the mass asymmetry degree of freedom