PIONIC FUSION OF HEAVY-IONS

We report the first experimental observation of the pionic fusion of t wo heavy ions. The C-12(C-12,Mg-24)pi(0) and C-12(C-12,Na-24)pi(+) cro ss sections have been measured to be 208 +/- 38 and 182 +/- 84 pb, res pectively, at E(cm) = 137 MeV. This cross section for heavy-ion pion p roduction, at an energy just 6 MeV above the absolute energy-conservat ion Limit, constrains possible production mechanisms to incorporate th e kinetic energy of the entire projectile-target system as well as the binding energy gained in fusion.