First Measurement of the Branching Ratio of $J/\ddot{I}ˆ\to {\hat{I}}^3{f}_2(1270)f_2(1270)$

Abstract

Using 58 million $J/\ddot{I}ˆ$ events taken with the BES II detector at the Beijing Electron Positron Collider, a new decay mode $J/\ddot{I}ˆ\to {\hat{I}}^3{f}_2(1270)f_2(1270)\to {\hat{I}}^3\ddot{I}{€}^{+}\ddot{I}{€}^{-}\ddot{I}{€}^{+}\ddot{I}{€}^{-}$ is observed for the first time. The branching ratio is determined to be $Br(J/\ddot{I}ˆ\to {\hat{I}}^3{f}_2(1270)f_2(1270))=(9.5\pm 0.7\pm 1.6)\times 10^{-4}$, where the quoted errors are statistical and systematic, respectively.

7 pages, 3 figures