Observation of the Decay K^+ --> pi^+ gamma gamma
High Energy Physics - Experiment
2008-11-26 v2
Abstract
The first observation of the decay K^+ --> pi^+ gamma gamma is reported. A total of 31 events was observed with an estimated background of 5.1 +- 3.3 events in the pi+ momentum range from 100 MeV/c to 180 MeV/c. The corresponding partial branching ratio, B(K+ -> pi+ gamma gamma, 100 MeV/c < P_pi^+ < 180 MeV/c), is (6.0 +- 1.5 (stat) +- 0.7 (sys)) x 10^{-7}. No K^+ --> pi^+ gamma gamma decay was observed in the pi^+ momentum region greater than 215 MeV/c. The observed pi^+ momentum spectrum is compared with the predictions of chiral perturbation theory.
Cite
@article{arxiv.hep-ex/9708011,
title = {Observation of the Decay K^+ --> pi^+ gamma gamma},
author = {E787 Collaboration and P. Kitching and T. Nakano and M. Rozon and R. Soluk and S. Adler and M. S. Atiya and I-H. Chiang and J. S. Frank and J. S. Haggerty and T. F. Kycia and K. K. Li and L. S. Littenberg and A. Sambamurti and A. Stevens and R. C. Strand and C. Witzig and W. C. Louis and D. S. Akerib and M. Ardebili and M. Convery and M. M. Ito and D. R. Marlow and R. A. McPherson and P. D. Meyers and M. A. Selen and F. C. Shoemaker and A. J. S. Smith and E. W. Blackmore and D. A. Bryman and L. Felawka and A. Konaka and Y. Kuno and J. A. Macdonald and T. Numao and P. Padley and J. -M. Poutissou and R. Poutissou and J. Roy and A. S. Turcot},
journal= {arXiv preprint arXiv:hep-ex/9708011},
year = {2008}
}
Comments
9 pages, LaTeX, 3 Postscript figures