Key points are not available for this paper at this time.
Based on 368. 5 pb^-1 of e^+e^- collision data collected at center-of-mass energies 4. 914 and 4. 946 GeV by the BESIII detector, the e^+e^- ₂₁ (3872) process is searched for the first time. No significant signal is observed and the upper limits at the 90\% confidence level on the product of the Born cross section (e^+e^- ₂₁ (3872) ) and the branching fraction B₂₁ (3872) ^+^- J/ at 4. 914 and 4. 946 GeV are set to be 0. 85 and 0. 96 pb, respectively. These measurements provide useful information for the production of the ₂₁ (3872) at e^+e^- collider and deepen our understanding about the nature of this particle.
Collaboration et al. (2024) studied this question.