Energy Dependence of Sensitive Radius of Optical Model Potential for ⁶Li+²⁰⁸Pb

The sensitive region is the most fundamental ingredient in the study of the optical model potential. In the present work, the sensitive regions of the potential of ⁶Li+²⁰⁸Pb were extracted and studied by using notch method. The results show that multi-peak structure is observed for both the sensitive regions of real and imaginary parts of the optical model potential. The inner sensitive region corresponds to the Coulomb barrier penetration process and the position of which does not vary with the interaction energy, while the outer sensitive region, which arising from the surface interaction process, presents strong dependence on the interaction energy. With the new sensitive region, the properties of the optical model potential of ⁶Li+²⁰⁸Pb were re-checked. The threshold anomaly, not the breakup threshold anomaly, is found in the imaginary part of the optical potential.