Search for $f_J(2220)$ in Radiative $J/\psi$ Decays

We present a search for $f_J(2220)$ production in radiative $J/\psi \to \gamma f_J(2220)$ decays using $460{\mathrm{fb}}^{-1}$ of data collected with the BABAR detector at the SLAC PEP-II $e^{+}{e}^{-}$ collider. The $f_J(2220)$ is searched for in the decays to $K^{+}{K}^{-}$ and $K_S^0{K}_S^0$. No evidence of this resonance is observed, and 90% confidence level upper limits on the product of the branching fractions for $J/\psi \to \gamma f_J(2220)$ and $f_J(2220)\to K^{+}{K}^{-}(K_S^0{K}_S^0)$ as a function of spin and helicity are set at the level of ${10}^{-5}$, below the central values reported by the Mark III experiment.

Figure 1

The distribution of $M_{\mathrm{rec}}^2$, the square of the recoiling mass against the $J/\psi \to \gamma K^{+}{K}^{-}$ (a) and $J/\psi \to \gamma K_S^0{K}_S^0$ (b) candidates, after all other selection criteria are applied for events in which the ISR photon is detected (open circle) or undetected (solid circle).

Figure 2

The $\gamma K^{+}{K}^{-}$ (a) and $\gamma K_S^0{K}_S^0$ (b) mass spectra after all selection criteria are applied. The points represent data, and the plain histograms show combinations having fit probability larger than 0.01. The estimated inclusive background in the final sample is shown as a filled histogram.

Figure 3

The fitted $K^{+}{K}^{-}$ (a) and $K_S^0{K}_S^0$ (b) mass spectra. The expected contributions of the inclusive background (plain histogram), $J/\psi \to \gamma f_2^{\prime }(1525)$ (cross-hatched histogram), and $J/\psi \to \gamma f_0(1710)$ (hatched histogram) are also shown. The results of the fits are displayed in the insets.