"Statistical Yrast Line" in Heavy-Ion Fusion Reactions

Fusion cross sections measured at high energies are parametrized in terms of a "statistical yrast line." This line lies parallel to the usual yrast line (given by the rigid-body moment of inertia, 2/5Mr₀²A5/3) but is shifted upward by an additional energy ΔQ. Most experimental fusion cross sections for systems with A80 are well reproduced with values of r₀=1.20±0.05 fm and ΔQ=10±2.5 MeV.