Absence of the threshold anomaly in the elastic scattering of the weakly bound projectile 7Li on 27Al

To study the conditions leading to the appearance of the threshold anomaly in systems involving weakly bound projectiles we measured elastic scattering cross sections for the Li-7+Al-27 system at ten different bombarding energies. The results were exhaustively analyzed using different optical model potentials. The similar behavior observed in all these analyses allows us to conclude that no threshold anomaly is found for the present system.