Study of the Annihilation of Stopped Antiprotons in Hydrogen: the Reaction
G. B. Chadwick, W. T. Davies, M. Derrick, C. J. B. Hawkins, J. H. Mulvey, D. Radojičić, C. A. Wilkinson, M. Cresti, S. Limentani, and R. Santangelo
Phys. Rev. Lett. 10, 62 (1963) - Published 15 January, 1963