What is the Source of the Narrow Positron Peaks Observed in Superheavy Collision Systems?

Schweppe, J., & Greenberg, J. S. (1986). What is the Source of the Narrow Positron Peaks Observed in Superheavy Collision Systems? In Weak and Electromagnetic Interactions in Nuclei (pp. 186–199). Springer Berlin Heidelberg. https://doi.org/10.1007/978-3-642-71689-8_42