Radiative decays of the $\ensuremath{\Upsilon}(1\mathrm{S})$ to a pair of charged hadrons

Radiative decays of the $Υ (1 S)$ to a pair of charged hadrons

S. B. Athar et al. (CLEO Collaboration)

Phys. Rev. D 73, 032001 – Published 3 February 2006

Abstract

Using data obtained with the CLEO III detector, running at the Cornell Electron Storage Ring (CESR), we report on a new study of exclusive radiative $Υ (1 S)$ decays into the final states $γ π^{+} π^{-}$ , $γ K^{+} K^{-}$ , and $γ p \bar{p}$ . We present branching ratio measurements for the decay modes $Υ (1 S) \to γ f_{2} (1270)$ , $Υ (1 S) \to γ f_{2}^{'} (1525)$ , and $Υ (1 S) \to γ K^{+} K^{-}$ ; helicity production ratios for $f_{2} (1270)$ and $f_{2}^{'} (1525)$ ; upper limits for the decay $Υ (1 S) \to γ f_{J} (2200)$ , with $f_{J} (2220) \to π^{+} π^{-}$ , $K^{+} K^{-}$ , $p \bar{p}$ ; and an upper limit for the decay $Υ (1 S) \to γ X (1860)$ , with $X (1860) \to γ p \bar{p}$ .