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arXiv · 0904.1394

Charmonium decays to gamma pi0, gamma eta, and gamma eta'

CLEO Collaboration·T. K. Pedlar
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Abstract

Using data acquired with the CLEO-c detector at the CESR e+e- collider, we measure branching fractions for J/psi, psi(2S), and psi(3770) decays to gamma pi0, gamma eta, and gamma eta'. Defining R_n = B[ psi(nS)-->gamma eta ]/B[ psi(nS)-->gamma eta' ], we obtain R_1 = (21.1 +- 0.9)% and, unexpectedly, an order of magnitude smaller limit, R_2 < 1.8% at 90% C.L. We also use J/psi-->gamma eta' events to determine branching fractions of improved precision for the five most copious eta' decay modes.

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CLEO Collaboration, T. K. Pedlar. 2009-06-07. Charmonium decays to gamma pi0, gamma eta, and gamma eta'. https://doi.org/10.1103/physrevd.79.111101

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