Partial wave analysis of J/ψ\to γϕϕ

Abstract

Using $5.8\times 10^{7}J/\ddot{I}ˆ$ events collected in the BESII detector, the radiative decay $J/\ddot{I}ˆ\to {\hat{I}}^3\ddot{I}•\ddot{I}•\to {\hat{I}}^3{K}^{+}{K}^{-}{K}_S^0{K}_L^0$ is studied. The $\ddot{I}•\ddot{I}•$ invariant mass distribution exhibits a near-threshold enhancement that peaks around 2.24 GeV/$c^2$. A partial wave analysis shows that the structure is dominated by a $0^{-+}$ state ($\hat{I}\cdot (2225)$) with a mass of $2.24_{-0.02}^{+0.03}{}_{-0.02}^{+0.03}$ GeV/$c^2$ and a width of $0.19\pm 0.03_{-0.04}^{+0.06}$ GeV/$c^2$. The product branching fraction is: $Br(J/\ddot{I}ˆ\to {\hat{I}}^3\hat{I}\cdot (2225))\cdot Br(\hat{I}\cdot (2225)\to \ddot{I}•\ddot{I}•)=(4.4\pm 0.4\pm 0.8)\times 10^{-4}$.

11 pages, 4 figures. corrected proof for journal