Evidence for f0(980)f0(980) production in chi_c0 decays

Abstract

Using a sample of 14 million $\psi(2S)$ events accumulated with the BES II detector, evidence for $f_0(980)f_0(980)$ production in $\chi_{c0}$ decays is obtained for the first time; the branching ratio is determined to be ${\cal B}(\chi_{c0}\to f_0(980)f_0(980)\to\pi^+\pi^-\pi^+\pi^-) = (7.6 \pm 1.9 ({\rm stat}) \pm 1.6 ({\rm syst})) \times 10^{-4}$. The significance of the $f_0(980)$ signal is about 4.6$\sigma$.