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arXiv · 2610.34655

Two-Pion Exchange Paradigm in Hadron-Hadron Interactions from Lattice QCD

Tetsuo Hatsuda
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Abstract

We study hadron-hadron interactions in (2+1)-flavor lattice QCD near the physical pion mass ($m_π\simeq 146\mathrm{MeV}$) using the HAL QCD method, with particular emphasis on two-pion exchange (TPE). The nucleon--flavor-singlet hadron potentials such as $ϕ$-$N$, $J/ψ$-$N$, and $η_c$-$N$ are found to be attractive at all distances. Moreover, in the long-range region where one-pion exchange is forbidden, we observe lattice signatures consistent with TPE dominance. These results demonstrate that the HAL QCD method can extract universal long-distance phenomena, such as TPE, directly from nonperturbative QCD dynamics.

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Tetsuo Hatsuda. 2026-10-26. Two-Pion Exchange Paradigm in Hadron-Hadron Interactions from Lattice QCD. https://doi.org/10.1016/j.jspc.2026.100341

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