Evidence for exotic Hadron contributions to Λ_{b}^{0}→J/ψpπ^{-} decays

Journal article

A full amplitude analysis of Λ_{b}^{0}→J/ψpπ^{-} decays is performed with a data sample acquired with the LHCb detector from 7 and 8 TeV pp collisions, corresponding to an integrated luminosity of 3  fb^{-1}. A significantly better description of the data is achieved when, in addition to the previously observed nucleon excitations N→pπ^{-}, either the P_{c}(4380)^{+} and P_{c}(4450)^{+}→J/ψp states, previously observed in Λ_{b}^{0}→J/ψpK^{-} decays, or the Z_{c}(4200)^{-}→J/ψπ^{-} state, previously reported in B^{0}→J/ψK^{+}π^{-} decays, or all three, are included in the amplitude models. The data support a model containing all three exotic states, with a significance of more than three standard deviations. Within uncertainties, the data are consistent with the P_{c}(4380)^{+} and P_{c}(4450)^{+} production rates expected from their previous observation taking account of Cabibbo suppression.

Authors: Aaij, R; Abellán Beteta, C; Adeva, B; Adinolfi, M; Ajaltouni, Z

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Physical Society
• Journal: Physical Review Letters
• Volume: 117
• Issue: 8
• Article number: 082003
• Publication date: 2016-08-18
• Acceptance date: 2016-07-28
• DOI: 10.1103/PhysRevLett.117.082003
• EISSN: 1079-7114
• ISSN: 0031-9007
• Pmid: 27588849
• Language: English
• Keywords: LHCb Collaboration