Precision Measurement of the Mass and Lifetime of the Ξ0b Baryon

Using a proton-proton collision data sample corresponding to an integrated luminosity of 3     fb − 1 collected by LHCb at center-of-mass energies of 7 and 8 TeV, about 3800 Ξ 0 b → Ξ + c π − , Ξ + c → p K − π + signal decays are reconstructed. From this sample, the first measurement of the Ξ 0 b ba...

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Detalles Bibliográficos
Autores: Badalov, Alexey, Calvo Gómez, Míriam, Camboni, Alessandro, Garrido Beltrán, Lluís, Gascón Fora, David, Graciani Díaz, Ricardo, Graugés Pous, Eugeni, Marin Benito, Carla, Picatoste Olloqui, Eduardo, Rives Molina, Vicente José, Ruiz, Hugo (Ruiz Pérez), Vilasis-Cardona, Xavier, LHCb Collaboration
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2014
País:España
Institución:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositorio:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:2445/133085
Acceso en línea:https://hdl.handle.net/2445/133085
Access Level:acceso abierto
Palabra clave:Física de partícules
Experiments
Particle physics
Descripción
Sumario:Using a proton-proton collision data sample corresponding to an integrated luminosity of 3     fb − 1 collected by LHCb at center-of-mass energies of 7 and 8 TeV, about 3800 Ξ 0 b → Ξ + c π − , Ξ + c → p K − π + signal decays are reconstructed. From this sample, the first measurement of the Ξ 0 b baryon lifetime is made, relative to that of the Λ 0 b baryon. The mass differences M ( Ξ 0 b ) − M ( Λ 0 b ) and M ( Ξ + c ) − M ( Λ + c ) are also measured with precision more than 4 times better than the current world averages. The resulting values are τ Ξ 0 b τ Λ 0 b = 1.006 ± 0.018 ± 0.010 , M ( Ξ 0 b ) − M ( Λ 0 b ) = 172.44 ± 0.39 ± 0.17     MeV / c 2 , M ( Ξ + c ) − M ( Λ + c ) = 181.51 ± 0.14 ± 0.10     MeV / c 2 , where the first uncertainty is statistical and the second is systematic. The relative rate of Ξ 0 b to Λ 0 b baryon production is measured to be f Ξ 0 b f Λ 0 b B ( Ξ 0 b → Ξ + c π − ) B ( Λ 0 b → Λ + c π − ) B ( Ξ + c → p K − π + ) B ( Λ + c → p K − π + ) = ( 1.88 ± 0.04 ± 0.03 ) × 1 0 − 2 , where the first factor is the ratio of fragmentation fractions, b → Ξ 0 b relative to b → Λ 0 b . Relative production rates as functions of transverse momentum and pseudorapidity are also presented.