Speaker
Description
This abstract discusses three recent measurements conducted at BESIII on the cross-sections of electron-positron annihilation into hidden charm final states:
1) The Born cross-section for the reaction e+ e- → eta hc is measured at center-of-mass energies ranging from 4.129 to 4.600 GeV. A resonant structure in the cross-section line shape near 4.200 GeV is observed with a statistical significance of 7sigma; 2) Using e+e− collision data, corresponding to an integrated luminosity of 892pb−1 collected at center-of-mass energies from 4.84 to 4.95 GeV with the BESIII detector, we search for the process e+ e- → K+ K- psi(3770) by reconstructing two charged kaons and one D meson from psi(3770). No significant signal of e+ e- → K+ K- psi(3770) is found, and the upper limits of the Born cross-sections are reported at a 90% confidence level; 3) The energy-dependent cross-section for e+ e- → eta psi(2S) is measured at eighteen center-of-mass energies from 4.288 GeV to 4.951 GeV using the BESIII detector. Using the same data samples, we also perform the first search for the reaction e+ e−→ eta \tilde{X}(3872), but no evidence is found for the \tilde{X} in the pi+ pi- J/psi mass distribution.
