We report the first observation of double radiative capture on pionic hydrogen. The experiment was conducted at the TRIUMF cyclotron using the RMC spectrometer and detected [Formula presented]-ray coincidences following [Formula presented] stops in liquid hydrogen. We found the branching ratio for double radiative capture to be [Formula presented]. The measured branching ratio and angle-energy distributions support the theoretical prediction of a dominant contribution from the [Formula presented] annihilation mechanism.
|Journal||Physical Review Letters|
|State||Published - 2002|
Bibliographical noteFunding Information:
We wish to thank the staff of the TRIUMF laboratory for their support of this work. In particular, we acknowledge the help of Renée Poutissou on the data acquisition and Dennis Healey on the hydrogen target. In addition, we thank Douglas Beder and Harold Fearing for helpful discussions and the National Science Foundation (United States), the Natural Sciences and Engineering Research Council (Canada), the Henry Luce Foundation (JHDC), and the Jeffress Memorial Trust (DSA) for financial ?>support.
ASJC Scopus subject areas
- Physics and Astronomy (all)