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Please use this identifier to cite or link to this item: https://hdl.handle.net/2445/132876
Observation of J/ψp Resonances Consistent with Pentaquark States in Λ0b→J/ψK−p Decays
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Observations of exotic structures in the J / ψ p channel, which we refer to as charmonium-pentaquark states, in Λ 0 b → J / ψ K − p decays are presented. The data sample corresponds to an integrated luminosity of 3 fb − 1 acquired with the LHCb detector from 7 and 8 TeV p p collisions. An amplitude analysis of the three-body final state reproduces the two-body mass and angular distributions. To obtain a satisfactory fit of the structures seen in the J / ψ p mass spectrum, it is necessary to include two Breit-Wigner amplitudes that each describe a resonant state. The significance of each of these resonances is more than 9 standard deviations. One has a mass of 4380 ± 8 ± 29 MeV and a width of 205 ± 18 ± 86 MeV , while the second is narrower, with a mass of 4449.8 ± 1.7 ± 2.5 MeV and a width of 39 ± 5 ± 19 MeV . The preferred J P assignments are of opposite parity, with one state having spin 3 / 2 and the other 5 / 2 .
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BADALOV, Alexey, et al. Observation of J/ψp Resonances Consistent with Pentaquark States in Λ0b→J/ψK−p Decays. Physical Review Letters. 2015. Vol. 115, num. 7, pags. 072001. ISSN 0031-9007. [consulted: 8 of August of 2026]. Available at: https://hdl.handle.net/2445/132876