Further Experimental Studies of Two-Body Radiative ΥDecays

Abstract

Continuing our studies of radiative Upsilon(1S) decays, we report on a search for Upsilon to gamma eta and Upsilon to gamma f_{J}(2220) in 61.3 pb^{-1} of e^{+}e^{-} data taken with the CLEO II detector at the Cornell Electron Storage Ring. For the gamma eta search the three decays of the eta meson to pi^{+}pi^{-}pi^{0}, pi^{0}pi^{0}pi^{0}, and gamma gamma were investigated. We found no candidate events in the two (3π)^{0} modes and no significant excess over expected backgrounds in the gamma gamma mode to set a limit on the branching fraction of B(Upsilon to gamma eta) < 2.1 x 10^{-5} at 90% C.L. The three charged two-body final states h h-bar (h = pi^{+}, K^{+}, p) were investigated for f_{J}(2220) production, with one, one, and two events found, respectively. Limits at 90% C.L. of B(Υto gamma f_{J}) x B(f_{J} to h h-bar) ~ 1.5 x 10^{-5} have been set for each of these modes. We compare our results to measurements of other radiative Upsilon decays, to measurements of radiative J/psi decays, and to theoretical predictions.

19 pages postscript, also available through http://w4.lns.cornell.edu/public/CLNS, submitted to Physical Review D

References in corpus (1)

• Search for the Decay ${\rm Y}(1S)\to \gamma {\eta }^{{}^{\prime }}$

Cited by in corpus (7)

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• Possible Hints and Search for Glueball Production in Charmless Rare B Decays
• Search for Radiative Decays of Upsilon(1S) into eta and eta'
• Radiative Decay of ${\rm Y}$ into a Scalar Glueball
• Scalar charmonium and glueball mixing in $e^{+}{e}^{-}\to J/\psi X$
• ${\rm Y}$ radiative decays to light quark jets and color octet mechanism