第八十六期HAPOF论坛, Global coupled-channel analysis of 𝒆+𝒆−→𝒄𝒄 ̅ processes in √𝒔=𝟑.𝟕𝟓−𝟒.𝟕 GeV, Satoshi Nakamura 教授

Friday 12 Jan 2024, 15:00 → 17:00 Asia/Shanghai

报告人：Satoshi Nakamura 教授（山东大学）
报告时间：2024年01月12日 15：00 - 17：00 (Beijing time)
会议链接：点击链接
腾讯会议室ID: 857-212-027    

摘要：
Recent high-precision e^+e^-→cc_bar data from the BESIII and Belle are highly useful to 
understand the vector charmonium pole structure and puzzling line shapes due to the exotic
hadron candidates Y. We thus conduct a global coupled-channel analysis of most of the 
available data (9 two-body, 8 three-body, and 1 four-body final states) in √s=3.75-4.7GeV.
Not only cross sections but also invariant mass distributions of subsystems are fitted. 
Our model includes dozens of (quasi) two-body states that nonperturbatively couple with 
each other through bare charmonium excitations and particle-exchange mechanisms required 
by the three-body unitarity. The amplitudes obtained from the fits are analytically 
continued to vector charmonium and Z_c poles. We do not find a ψ(4160) pole that has been 
considered well-established. Instead, we find two poles of ∼4230MeV; ψ(4230) with Γ=36MeV 
and a broader one with Γ=114MeV. Two Z_c poles are found as virtual states ∼40MeV below the 
D∗ D∗_bar thresholds, being consistent with lattice QCD results. This work presents the 
first global analysis to determine the vector charmonium and Z_c poles, thereby paving the 
way to extracting detailed properties of the prominent exotic hadron candidates from data. 
This presentation is based on arXiv:2312.17658.

报告人简介：
Satoshi Nakamura, 山东大学副教授. He got his PhD from Osaka University in 2003. He worked at
several places such as TRIUMF, JLab, and USTC as postdoctoral researcher. From 2023, he 
works at Shandong University as an associate professor. Through his career, he developed
many reaction models of few-hadron systems for hadron spectroscopy(amplitude analyses), 
neutrino oscillation experiments, and astrophysical applications.

特别鸣谢：本届论坛由国家自然科学基金委重点项目资金支持。

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