Observation of J/ψp Resonances Consistent with Pentaquark States in Λ0b→J/ψK−p Decays
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 amplit...
| Autores: | , , , , , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2015 |
| País: | España |
| Institución: | Universidad de Barcelona |
| Repositorio: | Dipòsit Digital de la UB |
| OAI Identifier: | oai:diposit.ub.edu:2445/132876 |
| Acceso en línea: | https://hdl.handle.net/2445/132876 |
| Access Level: | acceso abierto |
| Palabra clave: | Física de partícules Experiments Particle physics |
| Sumario: | 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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