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arXiv · 2504.03392

Two-pole structures in QCD -- a universal phenomenon governed by chiral dynamics

Jia-Ming Xie·Jun-Xu Lu·Li-Sheng Geng·Bing-Song Zou
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Abstract

We illustrate how the two-pole structures of the $Λ(1405)$ emerge from the underlying universal chiral dynamics that describe the coupled-channel interactions between octet baryons and pseudo-Nambu-Goldstone bosons. Specifically, we attribute this phenomenon to the form of the leading-order chiral potential, which is of the Weinberg-Tomozawa type. We reveal how the underlying chiral dynamics can be exposed by examining the light-quark mass evolution of the two poles. The latest lattice QCD simulations have indeed found evidence for the existence of the two poles of $Λ(1405)$, in qualitative agreement with our predictions. We briefly mention a recent work in which lattice QCD simulations are studied more quantitatively, along with a proposal for how the SU(3) flavor content of the two poles of $Λ(1405)$ can be experimentally verified.

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Jia-Ming Xie, Jun-Xu Lu, Li-Sheng Geng, Bing-Song Zou. 2025-04-04. Two-pole structures in QCD -- a universal phenomenon governed by chiral dynamics. https://arxiv.org/abs/2504.03392

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