Measurements of the Mass and Full-Width of the $\hat{I}{\cdot }_c$ Meson

Abstract

In a sample of 58 million $J/\ddot{I}ˆ$ events collected with the BES II detector, the process J/$\ddot{I}ˆ\to {\hat{I}}^3\hat{I}{\cdot }_c$ is observed in five different decay channels: ${\hat{I}}^3{K}^{+}{K}^{-}\ddot{I}{€}^{+}\ddot{I}{€}^{-}$, ${\hat{I}}^3\ddot{I}{€}^{+}\ddot{I}{€}^{-}\ddot{I}{€}^{+}\ddot{I}{€}^{-}$, ${\hat{I}}^3{K}^{\pm }{K}_S^0\ddot{I}{€}^{\mp }$ (with $K_S^0\to \ddot{I}{€}^{+}\ddot{I}{€}^{-}$), ${\hat{I}}^3\ddot{I}•\ddot{I}•$ (with $\ddot{I}•\to K^{+}{K}^{-}$) and ${\hat{I}}^{3}p\bar{p}$. From a combined fit of all five channels, we determine the mass and full-width of $\hat{I}{\cdot }_c$ to be $m_{\hat{I}{\cdot }_c}=2977.5\pm 1.0(stat.)\pm 1.2(syst.)$ MeV/$c^2$ and $\hat{I}{“}_{\hat{I}{\cdot }_c}=17.0\pm 3.7(stat.)\pm 7.4(syst.)$ MeV/$c^2$.

9 pages, 2 figures and 4 table. Submitted to Phys. Lett. B