Unquenched Charmonium and Beyond

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Bai, Zi-Yue, Chen, Dian-Yong, Qi-Huang, Liu, Xiang, Luo, Si-Qiang, Wang, Jun-Zhang
Format: Preprint
Published: 2026
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866917288722038784
author Bai, Zi-Yue
Chen, Dian-Yong
Qi-Huang
Liu, Xiang
Luo, Si-Qiang
Wang, Jun-Zhang
author_facet Bai, Zi-Yue
Chen, Dian-Yong
Qi-Huang
Liu, Xiang
Luo, Si-Qiang
Wang, Jun-Zhang
contents The year 2024 marked the 50th anniversary of the discovery of the $J/ψ$ particle, which unveiled the charm quark and the charmonium spectrum, instigating the "November Revolution" in particle physics. This discovery catalyzed the development of quenched potential models, most notably the Cornell model, which provided a foundational quantitative description of the hadronic spectrum. However, the landscape of hadron spectroscopy has been profoundly transformed since the turn of the 21st century with the observation of numerous charmonium-like states, such as $X(3872)$, which exhibit properties starkly at odds with quenched model predictions. These discrepancies, exemplified by the "$X(3872)$ low-mass puzzle" and the "$Y$ problem" associated with vector states like $Y(4260)$, underscore the critical limitations of the quenched approximation and signal the necessity for a new theoretical paradigm. This review synthesizes recent advances in hadronic spectroscopy, arguing that the unquenched picture, which incorporates coupled-channel effects such as hadronic loops, is essential for a unified description of these new states and associated anomalies. We demonstrate how unquenched effects provide compelling solutions to long-standing puzzles in charmonium decays (e.g., the "$ρπ$ puzzle" and anomalous dipion transitions), predict and explain the existence of exotic charged states like $Z_c(3900)$ and $Z_b(10610)$ via mechanisms such as Initial Single Pion Emission, and offer a framework for understanding interactions between charmonia and with nucleons. Furthermore, we emphasize the universality of unquenched effects, extending their application to bottomonium and light-flavor sectors. With improving precision, we advocate systematic development of unquenched hadronic spectroscopy.
format Preprint
id arxiv_https___arxiv_org_abs_2602_19887
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Unquenched Charmonium and Beyond
Bai, Zi-Yue
Chen, Dian-Yong
Qi-Huang
Liu, Xiang
Luo, Si-Qiang
Wang, Jun-Zhang
High Energy Physics - Phenomenology
High Energy Physics - Experiment
High Energy Physics - Lattice
Nuclear Theory
The year 2024 marked the 50th anniversary of the discovery of the $J/ψ$ particle, which unveiled the charm quark and the charmonium spectrum, instigating the "November Revolution" in particle physics. This discovery catalyzed the development of quenched potential models, most notably the Cornell model, which provided a foundational quantitative description of the hadronic spectrum. However, the landscape of hadron spectroscopy has been profoundly transformed since the turn of the 21st century with the observation of numerous charmonium-like states, such as $X(3872)$, which exhibit properties starkly at odds with quenched model predictions. These discrepancies, exemplified by the "$X(3872)$ low-mass puzzle" and the "$Y$ problem" associated with vector states like $Y(4260)$, underscore the critical limitations of the quenched approximation and signal the necessity for a new theoretical paradigm. This review synthesizes recent advances in hadronic spectroscopy, arguing that the unquenched picture, which incorporates coupled-channel effects such as hadronic loops, is essential for a unified description of these new states and associated anomalies. We demonstrate how unquenched effects provide compelling solutions to long-standing puzzles in charmonium decays (e.g., the "$ρπ$ puzzle" and anomalous dipion transitions), predict and explain the existence of exotic charged states like $Z_c(3900)$ and $Z_b(10610)$ via mechanisms such as Initial Single Pion Emission, and offer a framework for understanding interactions between charmonia and with nucleons. Furthermore, we emphasize the universality of unquenched effects, extending their application to bottomonium and light-flavor sectors. With improving precision, we advocate systematic development of unquenched hadronic spectroscopy.
title Unquenched Charmonium and Beyond
topic High Energy Physics - Phenomenology
High Energy Physics - Experiment
High Energy Physics - Lattice
Nuclear Theory
url https://arxiv.org/abs/2602.19887