Total cross section of n+6Li and n+7Li scattering by three-cluster formulation

The scattering and reaction cross sections for n+7Li system are examined with a multiconfiguration and multichannel resonating-group calculation utilizing a three-cluster formulation for α+3N+N system. The incorporated channels are n+7Li, n+7Li*, t+5He, and 4H+α, where 7Li* is the excited state of 7Li having t+α structure with the relative orbital angular momentum I=3. The obtained energy spectrum of 8Li has a very nice agreement with the R-matrix predictions by Knox and Lane. The total elastic cross section for n+7Li scattering is overestimated by about 15-20 %. For the total reaction cross section, the present calculation yields only 50-60 % of the experimental value, which is a consistent conclusion with the previous result of the seven-nucleon system in terms of the similar model. (author)