The 6He and 6Li interaction with 12C at energies of 20 – 50 MeV/nucleon

The elastic scattering data for $^{6}$He+$^{12}$C [1] when plotted on top of similar $^{6}$Li+$^{12}$C data [2] shows that the absorption of $^{6}$He is weaker than $^{6}$Li, a surprising result since $^{6}$He has a much lower binding energy (0.98 MeV) than does $^{6}$Li (1.47 MeV). In order to understand the origin of this surprising result the elastic scattering cross sections for $^{6}$He and $^{6}$Li by $^{12}$C in the energy range 20 – 50 MeV/nucleon were analyzed using coupled reaction channels (CRC) calculations that employed optical potentials of Woods-Saxon type, double-folded (DF) and cluster-folded (CF) potentials. The results of these calculations and possible reasons for the weaker absorption of $^{6}$He relative to $^{6}$Li will be presented. \newline [1] V. Lapoux et al Phys. Rev. C 66, 034608 (2002) \newline [2] A. Nadasen et al Phys. Rev. C 37, 132 (1988) A. Nadasen et al ibid C 37, 674 (1993)