Measurements of B(¯¯¯B0→Λ+c¯p) and B(B−→Λ+c¯pπ−) and studies of Λ+cπ− resonances

We present an investigation of the decays ¯¯¯ B 0 → Λ + c ¯ p and B − → Λ + c ¯ p π − based on 383 × 10 6 Υ ( 4 S ) → B ¯¯¯ B decays recorded with the BABAR detector. We measure the branching fractions of these decays; their ratio is B ( B − → Λ + c ¯ p π − ) / B ( ¯¯¯ B 0 → Λ + c ¯ p ) = 15.4 ± 1.8...

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Detalles Bibliográficos
Autores: Garra Ticó, Jordi, Graugés Pous, Eugeni, BABAR Collaboration
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2008
País:España
Institución:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/131515
Acceso en línea:https://hdl.handle.net/2445/131515
Access Level:acceso abierto
Palabra clave:Física de partícules
Experiments
Particle physics
Descripción
Sumario:We present an investigation of the decays ¯¯¯ B 0 → Λ + c ¯ p and B − → Λ + c ¯ p π − based on 383 × 10 6 Υ ( 4 S ) → B ¯¯¯ B decays recorded with the BABAR detector. We measure the branching fractions of these decays; their ratio is B ( B − → Λ + c ¯ p π − ) / B ( ¯¯¯ B 0 → Λ + c ¯ p ) = 15.4 ± 1.8 ± 0.3 . The B − → Λ + c ¯ p π − process exhibits an enhancement at the Λ + c ¯ p threshold and is a laboratory for searches for excited charm baryon states. We observe the resonant decays B − → Σ c ( 2455 ) 0 ¯ p and B − → Σ c ( 2800 ) 0 ¯ p but see no evidence for B − → Σ c ( 2520 ) 0 ¯ p . This is the first observation of the decay B − → Σ c ( 2800 ) 0 ¯ p ; however, the mass of the observed excited Σ 0 c state is ( 2846 ± 8 ± 10 )     MeV / c 2 , which is somewhat inconsistent with previous measurements. Finally, we examine the angular distribution of the B − → Σ c ( 2455 ) 0 ¯ p decays and measure the spin of the Σ c ( 2455 ) 0 baryon to be 1 / 2 , as predicted by the quark model.