First Observation of $\Upsilon(1S)\to \gamma\pi\pi$
High Energy Physics - Experiment
2010-04-08 v1
Abstract
We report on a study of exclusive radiative decays of the Upsilon(1S) resonance collected with the CLEO-II detector operating at CESR. We present the first observation of the radiative decays Upsilon(1S)->gamma pi+pi- and Upsilon(1S)->gamma pi0pi0. For the dipion mass regime m(pipi)>1.0 GeV, we obtain Br(Upsilon(1S)->gamma pi+pi-=(6.3+/-1.2+/-1.3) x 10^(-5), and Br(Upsilon(1S)->gamma pi0pi0=(1.7+/-0.6+/-0.3) x 10^(-5). The observed gamma pipi events are consistent with the hypothesis Upsilon(1S)->gamma f2(1270).
Cite
@article{arxiv.hep-ex/9807031,
title = {First Observation of $\Upsilon(1S)\to \gamma\pi\pi$},
author = {A. Anastassov},
journal= {arXiv preprint arXiv:hep-ex/9807031},
year = {2010}
}
Comments
9 pages, postscript file also available through http://w4.lns.cornell.edu/public/CLNS