Covalent hadronic molecules via QCD sum rules


  • Rui-Rui Dong Southeast University
  • Hua-Xing Chen Southeast University
  • Niu Su Southeast University
  • Hong-Zhou Xi Southeast University
  • Yi-Xin Yan Southeast University



hadronic molecule, covalent bond, QCD sum rules


After carefully examining Feynman diagrams corresponding to the $\bar D \Sigma_c$ hadronic molecular state, we propose a possible binding mechanism induced by shared light quarks. We systematically study its corresponding light-quark-exchange interaction using the method of QCD sum rules, and the obtained results suggest that there can be the $\bar D \Sigma_c$ covalent molecule of $I=1/2$. Our QCD sum rule analyses further indicate a model-independent hypothesis: the light-quark-exchange interaction is attractive when the shared light quarks are totally antisymmetric so that obey the Pauli principle.


S. K. Choi et al., Observation of a Narrow Charmoniumlike State in Exclusive Decays, Phys. Rev. Lett. 91 (2003) 262001,

P. A. Zyla et al., Review of Particle Physics, PTEP 2020 (2020) 083C01,

H.-X. Chen, et al., The hidden-charm pentaquark and tetraquark states, Phys. Rept. 639 (2016) 1,

A. Hosaka, et al., Exotic hadrons with heavy flavors: X, Y, Z, and related states, PTEP 2016 (2016) 062C01,

R. F. Lebed, R. E. Mitchell, and E. S. Swanson, Heavyquark QCD exotica, Prog. Part. Nucl. Phys. 93 (2017) 143,

A. Esposito, A. Pilloni, and A. D. Polosa, Multiquark resonances, Phys. Rept. 668 (2017) 1,

A. Ali, J. S. Lange, and S. Stone, Exotics: Heavy pentaquarks and tetraquarks, Prog. Part. Nucl. Phys. 97 (2017) 123,

F.-K. Guo et al., Hadronic molecules, Rev. Mod. Phys. 90 (2018) 015004,

S. L. Olsen, T. Skwarnicki, and D. Zieminska, Nonstandard heavy mesons and baryons: Experimental evidence, Rev. Mod. Phys. 90 (2018) 015003,

M. Karliner, J. L. Rosner, and T. Skwarnicki, Multiquark States, Ann. Rev. Nucl. Part. Sci. 68 (2018) 17,

N. Brambilla, et al., The XY Z states: Experimental and theoretical status and perspectives, Phys. Rept. 873 (2020) 1,

S.Weinberg, Evidence That the Deuteron Is Not an Elementary Particle, Phys. Rev. 137 (1965) B672,

M. B. Voloshin and L. B. Okun, Hadron molecules and charmonium atom, JETP Lett. 23 (1976) 333

A. De Rujula, H. Georgi, and S. L. Glashow, Molecular Charmonium: A New Spectroscopy?, Phys. Rev. Lett. 38 (1977) 317,

R. Aaij et al., Observation of a Narrow Pentaquark State, Pc(4312)+, and of the Two-Peak Structure of the Pc(4450)+, Phys. Rev. Lett. 122 (2019) 222001,

J.-J. Wu, et al., Prediction of Narrow and Resonances with Hidden Charm above 4 GeV, Phys. Rev. Lett. 105 (2010) 232001,

Z.-C. Yang, et al., Possible hidden-charm molecular baryons composed of an anti-charmed meson and a charmed baryon, Chin. Phys. C 36 (2012) 6, 1674-1137/36/1/002.

M. Karliner and J. L. Rosner, New Exotic Meson and Baryon Resonances from Doubly-Heavy Hadronic Molecules, Phys. Rev. Lett. 115 (2015) 122001,

R. Chen, et al., Identifying Exotic Hidden-charm Pentaquarks, Phys. Rev. Lett. 115 (2015) 132002,

M.-Z. Liu et al., Emergence of a Complete Heavy-Quark Spin Symmetry Multiplet: Seven Molecular Pentaquarks in Light of the Latest LHCb Analysis, Phys. Rev. Lett. 122 (2019) 242001,

H.-X. Chen, Covalent hadronic molecules induced by shared light quarks (2021),




How to Cite

Dong R-R, Chen H-X, Su N, Xi H-Z, Yan Y-X. Covalent hadronic molecules via QCD sum rules. Supl. Rev. Mex. Fis. [Internet]. 2022 Aug. 1 [cited 2022 Dec. 7];3(3):0308036 1-4. Available from: