Search for $X(3872)$ in $\ensuremath{\gamma}\ensuremath{\gamma}$ Fusion and Radiative Production at CLEO

Search for $X (3872)$ in $γ γ$ Fusion and Radiative Production at CLEO

S. Dobbs et al. (CLEO Collaboration)

Phys. Rev. Lett. 94, 032004 – Published 27 January 2005

Abstract

We report on a search for the recently reported $X (3872)$ state using $15.1 {f b}^{- 1}$ of $e^{+} e^{-}$ data taken in the $\sqrt{s} = 9.46 - 11.30 G e V$ region. Separate searches for the production of the $X (3872)$ in untagged $γ γ$ fusion and $e^{+} e^{-}$ annihilation following initial state radiation are made by taking advantage of the unique angular correlation between the leptons from the decay $J / ψ \to l^{+} l^{-}$ in $X (3872)$ decay to $π^{+} π^{-} J / ψ$ . No signals are observed in either case, and $90 %$ confidence upper limits are established as $(2 J + 1) Γ_{γ γ} (X (3872)) B (X \to π^{+} π^{-} J / ψ) < 12.9 e V$ and $Γ_{e e} (X (3872)) B (X \to π^{+} π^{-} J / ψ) < 8.3 e V$ .