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Strange pentaquark molecules in QCD sum rules

¹Department of Physics and Center for High Energy Physics, Tsinghua University, Beijing 100084, China
²Center for High Energy Physics, Peking University, Beijing 100871, China

^*Contact author: bd@mail.tsinghua.edu.cn
^†Contact author: shqzhang@pku.edu.cn

Phys. Rev. D 114, 034030 – Published 13 August, 2026

DOI: https://doi.org/10.1103/hbtg-qny8

Abstract

We study hidden- and open-strange pentaquark configurations in the hadronic molecular picture with QCD sum rules. Starting from the baryon octet combined with an $s \bar{s}$ pair, we construct 21 interpolating currents with $J = 1 / 2$ and $3 / 2$ . In the analysis, contributions up to dimension 11 are included in the operator product expansion, and both parity-projected spectra and the chiral-even and chiral-odd Lorentz structures are examined. No bound-state solution is found in the $J^{P} = 1 / 2^{-}$ sector, although several channels generate resonance masses near nearby thresholds or poorly established strange baryons. In the $J^{P} = 3 / 2^{-}$ sector, the $Σ ϕ$ and $Ξ K^{*}$ currents both support a near-threshold bound-state solution around 2.2 GeV, suggesting a possible molecular configuration with channel mixing. In contrast, positive-parity sectors are more difficult to identify the corresponding states. In addition, our results favor the spin-parity assignments $J^{P} = 3 / 2^{-}$ for $Σ (2250)$ , $J^{P} = 1 / 2^{-}$ for $Σ (2455)$ , $Σ (2620)$ , and $Ξ (2370)$ , and $J^{P} = 3 / 2^{+}$ for $Ξ (2250)$ . These results provide a systematic QCD sum rule study of strange pentaquark molecular candidates in the strange sector.

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Phys. Rev. D 114, 034030– Published 13 August, 2026

Vol. 114, Iss. 3 — 1 August 2026

Received 30 December 2025
Accepted 16 July 2026

DOI: https://doi.org/10.1103/hbtg-qny8

Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP³.

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Strange pentaquark molecules in QCD sum rules

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