Poles and Poltergeists in $e^+ e^- \to D \bar D$ Data

Nils Hüsken; Richard F. Lebed; Ryan E. Mitchell; Eric S. Swanson; Ya-Qian Wang; Chang-Zheng Yuan

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arXiv · 2404.03896

Poles and Poltergeists in $e^+ e^- \to D \bar D$ Data

Nils Hüsken·Richard F. Lebed·Ryan E. Mitchell·Eric S. Swanson·Ya-Qian Wang·Chang-Zheng Yuan

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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 $\psi(3770)$.

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Nils Hüsken, Richard F. Lebed, Ryan E. Mitchell, Eric S. Swanson, Ya-Qian Wang, Chang-Zheng Yuan. 2024-04-05. Poles and Poltergeists in $e^+ e^- \to D \bar D$ Data. https://arxiv.org/abs/2404.03896

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