Pionic Fusion of Heavy Ions
  We report the first experimental observation of the pionic fusion of two heavy ions. The 12C(12C,24Mg)pi0 and 12C(12C,24Na)pi+ cross sections have been measured to be 208 +/- 38 and 182 +/- 84 picobarns, respectively, at E_cm = 137 MeV. This cross section for heavy-ion pion production, at an energy just 6 MeV above the absolute energy-conservation limit, constrains possible production mechanisms to incorporate the kinetic energy of the entire projectile-target system as well as the binding energy gained in fusion. 
D. Horn, G. C. Ball, D. R. Bowman, W. G. Davies, D. Fox, A.   Galindo-Uribarri, A. C. Hayes, G. Savard (Chalk River Laborato...