Study of e${}^{+}$e${}^{-}$ $\to \text{p}\overline{\text{p}}\ddot{I}{€}^0$ in the Vicinity of the $\ddot{I}ˆ\text{(3770)}$

Abstract

The process $e^{+}{e}^{-}\to p\overline{p}\ddot{I}{€}^0$ has been studied by analyzing data collected at $\sqrt{s}=3.773$ GeV, at $\sqrt{s}=3.650$ GeV, and during a $\ddot{I}ˆ(3770)$ line shape scan with the BESIII detector at the BEPCII collider. The Born cross section of $p\overline{p}\ddot{I}{€}^0$ in the vicinity of the $\ddot{I}ˆ(3770)$ is measured and the Born cross section of $\ddot{I}ˆ(3770)\to p\overline{p}\ddot{I}{€}^0$ is extracted considering interference between resonant and continuum production amplitudes. Two solutions with the same probability and a significance of 1.5$\ddot{I}ƒ$ are found, and the Born cross section of $\ddot{I}ˆ(3770)\to p\overline{p}\ddot{I}{€}^0$ is determined to be less than 0.22 pb at 90% confidence level and $33.8\pm 1.8\pm 2.1$ pb, respectively. Using the estimated cross section and a constant decay amplitude approximation, the cross section $\ddot{I}ƒ(p\overline{p}\to \ddot{I}ˆ(3770)\ddot{I}{€}^0)$ is calculated for the kinematic situation of the planned $\overline{\text{P}}\text{ANDA}$ experiment. The maximum cross section corresponding to the two solutions is expected to be less than $0.79$ nb at 90% confidence level and $122\pm 10$ nb at a center of mass energy of 5.26 GeV.