Observation of J/ψp Resonances Consistent with Pentaquark States in Λ_b^0 → J/ψK^-p Decays
R. Aaij · LHCb Collaboration
Summary
The LHCb collaboration at CERN's Large Hadron Collider reported the observation of exotic structures in the J/ψp invariant-mass spectrum of Λ_b^0 baryon decays, interpreted as hidden-charm pentaquark states. Two resonant states, labelled Pc(4380)+ and Pc(4450)+, were identified with high statistical significance. The result provided the first compelling evidence for pentaquarks, baryon-like states composed of five quarks.
Key findings
- Two J/ψp resonances were observed: Pc(4380)+ (~4380 MeV) and Pc(4450)+ (~4450 MeV).
- Each state was observed with a statistical significance exceeding 9 standard deviations.
- The states have minimal quark content of four quarks and one antiquark, consistent with pentaquarks.
Subjects & keywords
Cite this paper
R. Aaij [LHCb Collaboration] (2015). Observation of J/ψp Resonances Consistent with Pentaquark States in Λ_b^0 → J/ψK^-p Decays. Physical Review Letters. https://doi.org/10.1103/PhysRevLett.115.072001
@article{aaij2015observation,
author = {R. Aaij and {LHCb Collaboration}},
title = {Observation of J/ψp Resonances Consistent with Pentaquark States in Λ_b^0 → J/ψK^-p Decays},
journal = {Physical Review Letters},
year = {2015},
doi = {10.1103/PhysRevLett.115.072001},
url = {https://doi.org/10.1103/PhysRevLett.115.072001}
}