Skip to main content
Log in

All Heavy Tetraquarks:The Dynamical Diquark Model and Other Approaches

  • Published:
Moscow University Physics Bulletin Aims and scope

Abstract

The 2020 announcement by LHCb of a narrow structure \(X(6900)\) in the di-\(J/\psi\) spectrum—a potential \(c\bar{c}c\bar{c}\) state—has opened a new era in hadronic spectroscopy. In this talk, we briefly survey theory works preceding this event, examine key features of the observed spectrum, and then discuss how subsequent theory studies (including with the author’s own dynamical diquark model) have interpreted these features. We conclude with proposals for experiments capable of distinguishing competing interpretations.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1

Similar content being viewed by others

REFERENCES

  1. R. Aaij et al. (LHCb Collab.), ‘‘Observation of structure in the \(J/\psi\)-pair mass spectrum,’’ Sci. Bull. 65, 1983 (2020); arXiv: 2006.16957 [hep-ex].

  2. S. Durgut (CMS Collab.). http://meetings.aps.org/Meeting/APR18/Session /U09.6.

  3. L. Bland et al. (ANDY Collab.), ‘‘Observation of Feynman scaling violations and evidence for a new resonance at RHIC,’’ arXiv: 1909.03124 [nucl-ex] (2019).

  4. R. Aaij et al. (LHCb Collab.), ‘‘Search for beautiful tetraquarks in the \(\Upsilon(1S)\mu^{+}\mu^{-}\) invariant-mass spectrum,’’ J. High Energy Phys. 2018, 086 (2018); arXiv: 1806.09707 [hep-ex].

  5. A. Sirunyan et al. (CMS Collab.), ‘‘Measurement of the \(\Upsilon\)(1S) pair production cross section and search for resonances decaying to \(\Upsilon\)(1S)\(\mu^{+}\mu^{-}\) in proton-proton collisions at \(\sqrt{s}=\) 13 TeV,’’ Phys. Lett. B 808, 135578 (2020); arXiv: 2002.06393 [hep-ex].

  6. R. Maciuła, W. Schäfer, and A. Szczurek, ‘‘On the mechanism of \(T_{4c}\)(6900) tetraquark production’’ Phys. Lett. B 812, 136010 (2021); arXiv: 2009.02100 [hep-ph].

  7. J. Zhao, S. Shi, and P. Zhuang, ‘‘Fully-heavy tetraquarks in a strongly interacting medium,’’ Phys. Rev. D 102, 114001 (2020); arXiv: 2009.10319 [hep-ph].

  8. A. Esposito, C. Manzari, A. Pilloni, and A. Polosa, ‘‘Hunting for tetraquarks in ultra-pheripheral heavy ion collisions,’’ Phys. Rev. D 104, 114029 (2021); arXiv: 2109.10359 [hep-ph].

  9. R. Lebed, R. Mitchell, and E. Swanson, ‘‘Heavy-quark QCD exotica,’’ Prog. Part. Nucl. Phys. 93, 143 (2017); arXiv: 1610.04528 [hep-ph].

  10. P. Zyla et al. (Particle Data Group), ‘‘Review of particle physics,’’ Prog. Theor. Exp. Phys. 2020, 083C01 (2020).

  11. C. Gong, M.-C. Du, Q. Zhao, X.-H. Zhong, and B. Zhou, ‘‘Nature of \(X(6900)\) and its production mechanism at LHCb,’’ Phys. Lett. B 824, 136794 (2022); arXiv: 2011.11374 [hep-ph].

  12. X.-K. Dong, V. Baru, F.-K. Guo, C. Hanhart, A. Ne- fediev, and B.-S. Zou, ‘‘Is the existence of a \(J/\psi J/\psi\) bound state plausible?,’’ Sci. Bull. 66, 1577 (2021); arXiv: 2107.03946 [hep-ph].

  13. Y. Iwasaki, ‘‘A possible model for new resonances-exotics and hidden charm,’’ Prog. Theor. Phys. 54, 492 (1975).

    Article  ADS  Google Scholar 

  14. J. Aubert et al. (E598 Collab.), ‘‘Experimental observation of a heavy particle \(J\),’’ Phys. Rev. Lett. 33, 1404 (1974).

    Article  ADS  Google Scholar 

  15. J. Augustin et al. (SLAC-SP-017), ‘‘Discovery of a narrow resonance in \(e^{+}e^{-}\) annihilation,’’ Phys. Rev. Lett. 33, 1406 (1974).

    Article  ADS  Google Scholar 

  16. A. Berezhnoy, A. Likhoded, A. Luchinsky, and A. Novoselov, ‘‘Double \(J/\psi\)-meson production at LHC and 4\(c\)-tetraquark state,’’ Phys. Rev. D 84, 094023 (2011); arXiv: 1101.5881 [hep-ph].

    Article  ADS  Google Scholar 

  17. A. Berezhnoy, A. Luchinsky, and A. Novoselov, ‘‘Tetraquarks composed of 4 heavy quarks,’’ Phys. Rev. D 86, 034004 (2012); arXiv: 1111.1867 [hep-ph].

    Article  ADS  Google Scholar 

  18. L. An (LHCb Collab.), ‘‘Latest results on exotic hadrons at LHCb,’’ (2020). https://indico.cern.ch/event/900972/

  19. J.-W. Zhu, X.-D. Guo, R.-Y. Zhang, W.-G. Ma, and X.-Q. Li, ‘‘A possible interpretation for \(X(6900)\) observed in four-muon final state by LHCb: A light Higgs-like boson?,’’ arXiv: 2011.07799 [hep-ph] (2020).

  20. X.-K. Dong, V. Baru, F.-K. Guo, C. Hanhart, and A. Nefediev, ‘‘Coupled-channel interpretation of the LHCb double-\(J/\psi\) spectrum and hints of a new state near the \(J/\psi J/\psi\) threshold,’’ Phys. Rev. Lett. 126, 132001 (2021).

    Article  ADS  Google Scholar 

  21. X.-K. Dong, V. Baru, F.-K. Guo, C. Hanhart, and A. Nefediev, Phys. Rev. Lett. 127, 119901(E) (2021); arXiv: 2009.07795 [hep-ph].

  22. Z.-H. Guo and J. Oller, ‘‘Insights into the inner structures of the fully charmed tetraquark state \(X(6900)\),’’ Phys. Rev. D 103, 034024 (2021); arXiv: 2011.00978 [hep-ph].

  23. J.-Z. Wang, D.-Y. Chen, X. Liu, and T. Matsuki, ‘‘Producing fully charm structures in the \(J/\psi\)-pair invariant mass spectrum,’’ Phys. Rev. D 103, 071503 (2021); arXiv: 2008.07430 [hep-ph].

  24. J. Sonnenschein and D. Weissman, ‘‘Deciphering the recently discovered tetraquark candidates around 6.9 GeV,’’ Eur. Phys. J. C 81, 25 (2021); arXiv: 2008.01095 [hep-ph].

  25. J. Giron and R. Lebed, ‘‘Simple spectrum of \(c\bar{c}c\bar{c}\) states in the dynamical diquark model,’’ Phys. Rev. D 102, 074003 (2020); arXiv: 2008.01631 [hep-ph].

  26. M. Karliner and J. Rosner, ‘‘Interpretation of structure in the Di-\(J/\psi\) spectrum,’’ Phys. Rev. D 102, 114039 (2020); arXiv: 2009.04429 [hep-ph].

  27. B.-C. Yang, L. Tang, and C.-F. Qiao, ‘‘Scalar fully-heavy tetraquark states \(QQ^{\prime}{\bar{Q}}\bar{Q^{\prime}}\) in QCD sum rules,’’ Eur. Phys. J. C 81, 324 (2021); arXiv: 2012.04463 [hep-ph].

  28. Z. Zhao, K. Xu, A. Kaewsnod, X. Liu, A. Limphirat, and Y. Yan, ‘‘Study of charmonium like and fully-charm tetraquark spectroscopy,’’ Phys. Rev. D 103, 116027 (2021); arXiv: 2012.15554 [hep-ph].

  29. C. Deng, H. Chen, and J. Ping, ‘‘Towards the understanding of fully-heavy tetraquark states from various models,’’ Phys. Rev. D 103, 014001 (2021); arXiv: 2003.05154 [hep-ph].

  30. M. Bedolla, J. Ferretti, C. Roberts, and E. Santopinto, ‘‘Spectrum of fully-heavy tetraquarks from a diquark+antidiquark perspective,’’ Eur. Phys. J. C 80, 1004 (2020); arXiv: 1911.00960 [hep-ph].

  31. R. Lebed, ‘‘Spectroscopy of exotic hadrons formed from dynamical diquarks,’’ Phys. Rev. D 96, 116003 (2017); arXiv: 1709.06097 [hep-ph].

  32. J.-M. Richard, ‘‘About the \(J/\psi\) \(J/\psi\) peak of LHCb: Fully-charmed tetraquark?,’’ Sci. Bull. 65, 1954 (2020); arXiv: 2008.01962 [hep-ph].

  33. Q.-F. Cao, H. Chen, H.-R. Qi, and H.-Q. Zheng, ‘‘Some remarks on \(X(6900)\),’’ Chin. Phys. C 45, 103102 (2021); arXiv: 2011.04347 [hep-ph].

Download references

Funding

This work was supported by the US National Science Foundation (NSF), grant nos. PHY- 18030912 and PHY-2110278.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to R. F. Lebed.

Ethics declarations

The author declares that he has no conflicts of interest.

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Lebed, R.F. All Heavy Tetraquarks:The Dynamical Diquark Model and Other Approaches. Moscow Univ. Phys. 77, 458–461 (2022). https://doi.org/10.3103/S002713492202059X

Download citation

  • Received:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.3103/S002713492202059X

Keywords:

Navigation