~6Li+^(208)Pb光学势灵敏半径的能量相依性

Energy Dependence of Sensitive Radius of Optical Model Potential for ~6Li+^(208)Pb

光学势灵敏区域的确定是研究光学势性质的先决要素。本工作利用扰动法,抽取并研究了弱束缚体系~6Li+^(208)Pb光学势灵敏区域的能量相依性。结果表明,该体系光学势实部和虚部的灵敏区域均呈现多峰结构。内部的灵敏区域对应体系库仑势垒的穿透过程,其位置基本不随能量的变化而改变;而外部的灵敏区域则对应体系的表面相互作用过程,并且存在强烈的能量相依性。采用新的灵敏区域重新检测了~6Li+^(208)Pb光学势的性质,结果表明在新的灵敏区域内,~6Li+^(208)Pb光学势虚部表现出传统的阈异常现象,而并非之前所观察到的破裂阈异常现象。

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.