Modeling pionic fusion

Recently observed rare heavy ion fusion processes, where the entire availab le energy is carried away by a single pion, is an example of extreme collec tivity in nuclear reactions. We calculate the cross section in the approxim ation of sudden overlap, modeling the initial and final nuclei by moving ha rmonic oscillator potentials. This allows for a fully quantum-mechanical tr eatment, exact conservation of linear and angular moments and fulfillment o f the Pauli principle. The results are in satisfactory agreement with data. Mass number dependence and general trends of the process are discussed. [S 0556-2813(99)03301-4].