The Abnormal Threshold Anomaly in the 6Li + 208Pb System

At present, there is a lack of sufficient experimental data in the near barrier and below barrier energy regions for weakly bound nuclear systems, and the behavior of their optical potentials is still controversial. This study measured the optical potential of the 6Li+208Pb system at near and deep barrier energies, providing data for further investigation of anomalous threshold phenomena. Measure the elastic scattering angle distribution of the 6Li+208Pb system, and then use an optical model to fit its elastic scattering angle distribution to extract optical potential parameters. The detector used in the experiment is a PIN detector, with a measurement angle range of 25 ◦ to 170 ◦. The measured energy is 20.22-32.02 MeV in the laboratory system, and the fitting program used is FRESCO. This dataset includes Table 1, which shows the distribution of elastic scattering angles measured at energies ranging from 20.22-32.02 MeV; Table 2 shows the distribution of elastic scattering angles under 20.22-32.02 MeV energy fitted and calculated by the FRESCO program. Tables 1 and 2 are both the distribution of elastic scattering angles in the center of mass system, and the cross-section is the relative cross-section, which is the ratio of elastic scattering cross-section to Rutherford scattering cross-section; Table 3 shows the optical potential parameters extracted from the elastic scattering angle distribution; Table 4 shows the optical potential parameters extracted from the elastic scattering angle distribution after fixing the geometric parameters; The real and imaginary parts (a) and (b) of the optical potential of the near barrier and under barrier energies in the 6Li+208Pb system at a sensitive radius RS=12.42 fm, as well as the optical potential maps of high-energy points reported in the literature