New LHCb pentaquarks as hadrocharmonium states

Michael I. Eides, Victor Yu Petrov, Maxim V. Polyakov

Research output: Contribution to journalArticlepeer-review

54 Scopus citations


New LHCb Collaboration results on pentaquarks with hidden charm1 are discussed. These results fit nicely in the hadrocharmonium pentaquark scenario.2,3, In the new data the old LHCb pentaquark Pc(4450) splits into two states Pc(4440) and Pc(4457). We interpret these two almost degenerated hadrocharmonium states with JP = 1/2- and JP = 3/2-, as a result of hyperfine splitting between hadrocharmonium states predicted in Ref. 2. It arises due to QCD multipole interaction between color-singlet hadrocharmonium constituents. We improve the theoretical estimate of hyperfine splitting2,3 that is compatible with the experimental data. The new Pc(4312) state finds a natural explanation as a bound state of ?c0 and a nucleon, with I = 1/2, JP = 1/2+ and binding energy 42 MeV. As a bound state of a spin-0 meson and a nucleon, hadrocharmonium pentaquark Pc(4312) does not experience hyperfine splitting. We find a series of hadrocharmonium states in the vicinity of the wide Pc(4380) pentaquark that can explain its apparently large decay width. We compare the hadrocharmonium and molecular pentaquark scenarios and discuss their relative advantages and drawbacks.

Original languageEnglish
Article number2050151
JournalModern Physics Letters A
Issue number18
StatePublished - Jun 14 2020

Bibliographical note

Publisher Copyright:
© 2020 World Scientific Publishing Company.


  • Pentaquark
  • hadrocharmonium
  • hidden charm

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Astronomy and Astrophysics
  • General Physics and Astronomy


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