Study of the P-wave charmonium state χ_{cJ} in ψ(2S) decays

Abstract

The processes $\ddot{I}ˆ(2S)\to {\hat{I}}^3\ddot{I}{€}^{+}\ddot{I}{€}^{-}$, ${\hat{I}}^3{K}^{+}{K}^{-}$ and ${\hat{I}}^{3}p\bar{p}$ have been studied using a sample of $3.7\times 10^6$ produced $\ddot{I}ˆ(2S)$ decays. We determine the total width of the $\ddot{I}{‡}_{c0}$ to be $\hat{I}{“}_{\ddot{I}{‡}_{c0}}^{tot}=14.3\pm 2.0\pm 3.0$ MeV. We present the first measurement of the branching fraction $B(\ddot{I}{‡}_{c0}\to p\bar{p})=(16.3\pm 4.4\pm 5.4)\times 10^{-5}$, where the first error is statistical and the second one systematic. Branching fractions of $\ddot{I}{‡}_{c0,2}\to \ddot{I}{€}^{+}\ddot{I}{€}^{-}$ and $K^{+}{K}^{-}$ are also reported.

10 pages, revtex, 3 figures, 2 tables