Light baryonium states with exotic quantum numbers

Bing-Dong Wan; Jun-Hao Zhang; Yan Zhang; Ming-Yang Yuan

doi:10.1140/epjc/s10052-026-15718-9

2025 Impact factor 4.9

Particles and Fields

Open Access

Eur. Phys. J. C (2026) 86: 493
https://doi.org/10.1140/epjc/s10052-026-15718-9

Regular Article - Theoretical Physics

Light baryonium states with exotic quantum numbers

Bing-Dong Wan¹^,2^a, Jun-Hao Zhang¹^,2, Yan Zhang¹^,2 and Ming-Yang Yuan¹^,2

¹ Department of Physics, Liaoning Normal University, 116029, Dalian, China
² Center for Theoretical and Experimental High Energy Physics, Liaoning Normal University, 116029, Dalian, China

^a This email address is being protected from spambots. You need JavaScript enabled to view it.

Received: 19 March 2026
Accepted: 15 April 2026
Published online: 7 May 2026

Abstract

The existence of baryonium-bound or resonant states composed of a baryon and an antibaryon has long been postulated as a natural extension of conventional hadron spectroscopy. In the present work, we conduct a systematic investigation of the mass spectrum and internal configurations of light baryonium candidates exhibiting exotic quantum numbers that are inaccessible within the framework of the traditional quark model. Employing the method of QCD sum rules, we analyze nucleon–antinucleon and light hyperon–anti-hyperon systems with quantum numbers $J^{PC} = 0^{- -}$ $Mathematical equation: $$J^{PC}=0^{--}$$$ and $0^{+ -}$ $Mathematical equation: $$0^{+-}$$$ , which are quantum number combinations prohibited for conventional mesonic states. Our analysis reveals the potential existence of two $0^{- -}$ $Mathematical equation: $$0^{--}$$$ $Λ$ $Mathematical equation: $$\Lambda $$$ - $\bar{Λ}$ $Mathematical equation: $$\bar{\Lambda }$$$ baryonium states with masses $(2.90 \pm 0.09)$ $Mathematical equation: $$(2.90\pm 0.09)$$$ GeV and $(3.36 \pm 0.09)$ $Mathematical equation: $$(3.36\pm 0.09)$$$ GeV, respectively, as well as two $0^{+ -}$ $Mathematical equation: $$0^{+-}$$$ $Λ$ $Mathematical equation: $$\Lambda $$$ - $\bar{Λ}$ $Mathematical equation: $$\bar{\Lambda }$$$ states with masses $(2.91 \pm 0.07)$ $Mathematical equation: $$(2.91\pm 0.07)$$$ GeV and $(3.29 \pm 0.07)$ $Mathematical equation: $$(3.29\pm 0.07)$$$ GeV, respectively. In addition, corresponding nucleon–antinucleon partner states are identified at $(2.69 \pm 0.07)$ $Mathematical equation: $$(2.69\pm 0.07)$$$ GeV, $(3.07 \pm 0.08)$ $Mathematical equation: $$(3.07\pm 0.08)$$$ GeV, $(2.86 \pm 0.07)$ $Mathematical equation: $$(2.86\pm 0.07)$$$ GeV, and $(3.22 \pm 0.07)$ $Mathematical equation: $$(3.22\pm 0.07)$$$ GeV, respectively. Furthermore, analogous $Ξ$ $Mathematical equation: $$\Xi $$$ - $\bar{Ξ}$ $Mathematical equation: $$\bar{\Xi }$$$ configurations are predicted with masses of $(3.10 \pm 0.09)$ $Mathematical equation: $$(3.10\pm 0.09)$$$ GeV, $(3.54 \pm 0.07)$ $Mathematical equation: $$(3.54\pm 0.07)$$$ GeV, $(3.08 \pm 0.08)$ $Mathematical equation: $$(3.08\pm 0.08)$$$ GeV, and $(3.45 \pm 0.08)$ $Mathematical equation: $$(3.45\pm 0.08)$$$ GeV, respectively. The possible decay modes of the light exotic baryonium states are analyzed, which are hopefully measurable in BESIII, BELLEII, and LHCb experiments.

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.

Funded by SCOAP³.

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Light baryonium states with exotic quantum numbers

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