Title: A unified coupled-channel description for the five near-threshold structures $ψ(3770)$, $G(3900)$, $R(3760)$, $R(3780)$ and $R(3810)$ from $e^+e^-$ annihilation Show Chinese title

Title: 对来自$e^+e^-$粒子湮灭的五个近阈值结构$ψ(3770)$、$G(3900)$、$R(3760)$、$R(3780)$和$R(3810)$的统一耦合通道描述

Abstract: The recent observation of multiple near-threshold structures in $e^+e^-$ annihilation-including $\psi(3770)$, $G(3900)$, $R(3760)$, $R(3780)$, and $R(3810)$-reveals limitations in existing models of charmonium and exotic hadrons. In this Letter, we propose a unified coupled-channel description that simultaneously incorporates all five near-threshold structures using parameters constrained by hadron spectroscopy. Our model accurately reproduces the line shapes in both $D\bar{D}$ and non-open-charm hadron (nOCH) channels, resolves the asymmetric profile of $\psi(3770)$, and produces the $G(3900)$ bump. We identify the $R(3780)$ as the dominant manifestation of $\psi(3770)$, attribute $R(3760)$ to $D\bar{D} \to \text{nOCH}$ rescattering and suggest that $R(3810)$ arises from coupling between the $\psi(1D)$ state and the $h_c\pi\pi$ channel. The significant non-$D\bar{D}$ decay of $\psi(3770)$ is explained by its near-threshold position. This analysis provides a coherent, unquenched framework centered on a charmonium $\psi(1D)$ core for near-threshold phenomena and offers a predictive approach extendable to bottomonium systems and future data from Belle II. Show Chinese abstract

Abstract: 最近在$e^+e^-$湮灭中观察到多个近阈值结构，包括$\psi(3770)$、$G(3900)$、$R(3760)$、$R(3780)$和$R(3810)$，揭示了现有底重子和奇特强子模型的局限性。在本文中，我们提出了一种统一的耦合通道描述，使用由强子谱学约束的参数，同时包含了所有五个近阈值结构。 我们的模型准确地再现了$D\bar{D}$和非开放魅夸克强子 (nOCH) 通道中的线形，解决了$\psi(3770)$的不对称轮廓，并产生了$G(3900)$的隆起。 我们将$R(3780)$识别为$\psi(3770)$的主要表现，将$R(3760)$归因于$D\bar{D} \to \text{nOCH}$的再散射，并认为$R(3810)$是来自$\psi(1D)$状态与$h_c\pi\pi$通道之间的耦合。 显著的非$D\bar{D}$衰变由$\psi(3770)$的近阈值位置解释。 此分析提供了一个以 charm 量子数$\psi(1D)$核心为中心的连贯、未抑制的框架，用于近阈值现象，并提供了一种可扩展到 bottom 量子数系统和 Belle II 未来数据的预测方法。