Analysis of BaBar, Belle, BES-II, CLEO and KEDR data on $\psi(3770)$ line shape and determination of the resonance parameters

TL;DR

This study analyzes data from multiple experiments on the $(3770)$ resonance to accurately determine its parameters, considering various theoretical models and systematic uncertainties.

Contribution

It provides a comprehensive combined analysis of $(3770)$ line shape data using multiple models and accounts for systematic uncertainties, leading to precise resonance parameter measurements.

Findings

Resonance mass: 3779.8 MeV

Total width: 25.8 MeV

Electron width: 196 eV

Abstract

The available data on the $D\overline{D}$ and inclusive hadronic cross sections in the $\psi(3770)$ region from the BaBar, Belle, BES-II, CLEO and KEDR experiments have been analyzed assuming that systematic uncertainties on cross sections measured by different detectors are not correlated. Four theoretical models predicting the $\psi(3770)$ line shape were considered for the $D\overline{D}$ channel. All of them gave satisfactory description of the data. The combined analysis of the $D\overline{D}$ and inclusive hadronic channel was performed using the model based on the vector dominance approach and accounting for the contribution of the $\psi(2S)$ tail to the $D\overline{D}$ cross section. The following values of the mass, total width, electron width and decay probability to the non-$D\overline{D}$ states were obtained: $M=3779.8 \pm 0.6 ~\text{MeV}, \Gamma=25.8 \pm 1.3 ~\text{MeV} , \Gamma_{ee}=196 \pm 18 ~\text{eV}, \mathcal{B}_{nD\overline{D}}=0.164 \pm 0.049$, where the errors quoted include both statistical and dominant systematic uncertainties.