Observation of Two New Ξ−b Baryon Resonances

Two structures are observed close to the kinematic threshold in the Ξ0bπ− mass spectrum in a sample of proton-proton collision data, corresponding to an integrated luminosity of 3.0  fb−1, recorded by the LHCb experiment. In the quark model, two baryonic resonances with quark content bds are expecte...

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Detalles Bibliográficos
Autores: Badalov, Alexey, Calvo Gomez, Miriam, Vilasis-Cardona, Xavier, LHCb Collaboration - CERN
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2015
País:España
Institución:Universitat Ramon Llull (URL)
Repositorio:DAU Arxiu Digital de la Universitat Ramon Llull
OAI Identifier:oai:dau.url.edu:20.500.14342/3092
Acceso en línea:http://hdl.handle.net/20.500.14342/3092
https://doi.org/10.1103/PhysRevLett.114.062004
Access Level:acceso abierto
Palabra clave:Gran col·lisionador d'hadrons (França i Suïssa)
Partícules (Física nuclear)
Protons
Col·lisions (Física nuclear)
539
Descripción
Sumario:Two structures are observed close to the kinematic threshold in the Ξ0bπ− mass spectrum in a sample of proton-proton collision data, corresponding to an integrated luminosity of 3.0  fb−1, recorded by the LHCb experiment. In the quark model, two baryonic resonances with quark content bds are expected in this mass region: the spin-parity JP=(1/2)+ and JP=(3/2)+ states, denoted Ξ'−b and Ξ*−b. Interpreting the structures as these resonances, we measure the mass differences and the width of the heavier state to be m(Ξ'−b)−m(Ξ0b)−m(π−)=3.653±0.018±0.006  MeV/c2, m(Ξ*−b)−m(Ξ0b)−m(π−)=23.96±0.12±0.06  MeV/c2, Γ(Ξ*−b)=1.65±0.31±0.10  MeV, where the first and second uncertainties are statistical and systematic, respectively. The width of the lighter state is consistent with zero, and we place an upper limit of Γ(Ξ'−b)<0.08  MeV at 95% confidence level. Relative production rates of these states are also reported.