12C+12C as the reference for reaction cross section

Background: In our previous paper, we tested the chiral (Kyushu) folding model for 12C+12C scattering, since the profile function in the Glauber mode is constructed for the system. We found that the folding model is reliable for reaction cross sections R in 30 < Elab < 100 MeV and 250 < Elab < 400 MeV. Accurate data are available for 12C scattering on 9Be, 12C, 27Al targets in 30 < Elab < 400 MeV.Purpose: We determine matter radius rm(exp) of 12C from the accurate R(exp), using the Kyushu g-matrix folding model.Results: Our result is r12m(exp) = 2.352 & PLUSMN;0.013 fm for 12C. The model is applied for the accurate data on 12C+27 Al scattering, and yields rm(exp) = 2.936 & PLUSMN; 0.012 fm for 27Al. Conclusion: Our conclusion is that rm(exp) = 2.352 & PLUSMN; 0.013 fm agrees with rm(exp) = 2.35 & PLUSMN; 0.02 fm determined from interaction cross sections by Tanihata et al.