1. Poles and Poltergeists in $e^+ e^- \to D \bar D$ Data
- Author
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Hüsken, Nils, Lebed, Richard F., Mitchell, Ryan E., Swanson, Eric S., Wang, Ya-Qian, and Yuan, Chang-Zheng
- Subjects
High Energy Physics - Phenomenology - Abstract
A recent report of $e^+ e^- \to D\bar D$ events by the BESIII Collaboration suggests the presence of a structure $R$ at 3900~MeV\@. We argue that this structure, called $G(3900)$ in the past, is not in fact due to a new $c\bar c$ resonance, but rather naturally emerges as a threshold enhancement due to the opening of the $D^*\bar D$ channel. We further find that the appearance of this structure does not require suppression because of a radial node in the $\psi(4040)$ wave function, although a node improves fit quality. The measured $e^+ e^-$ coupling of $\psi(4040)$ is found to be substantially smaller than previously estimated. In addition, we report new corrections to the measured cross section $\sigma(e^+ e^- \to D\bar D)$ at energies near $\psi(3770)$., Comment: Discussion of previous work updated. 9 pages, 8 figures
- Published
- 2024