Potential ''anomalies'' in 14N+27Al,28Si and 29Si systems

Seven elastic angular distributions and the fusion excitation functions for the 14N + 27AL, 14N + 28Si and 14N + 29Si systems with in the energy range 1.1<ECM/VB<2.5 are measured. The experimental fusion cross sections were superestimated by the simple one-dimensional barrier penetration model, with a ''frozen'' nuclear proximity potential. Through an effective variation of barrier height, the energy dependent corrections necessary to fit the data are calculated these corrections showed an ''anomalous'' behaviour in the above-barrier energy region. The corresponding imaginary potential parts were then constructed through the use of dispersion relation. (author)