Observation of the Ωb- baryon and measurement of the properties of the Ξb- and Ωb- baryons

We report the observation of the bottom, doubly-strange baryon Ωb- through the decay chain Ωb-→J/ψΩ-, where J/ψ→μ+μ-, Ω-→ΛK-, and Λ→pπ-, using 4.2  fb-1 of data from pp̅ collisions at √s=1.96  TeV, and recorded with the Collider Detector at Fermilab. A signal is observed whose probability of arising...

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Detalles Bibliográficos
Autores: Aaltonen, Timo Antero, Akimoto, Takashi, Álvarez González, Bárbara, Amerio, Silvia, Amidei, Dante, Anastassov, Anton, Annovi, Alberto, Antos, Jaroslav, Apollinari, Giorgio, Apresyan, Artur, Casal Laraña, Bruno, Cuevas Maestro, Francisco Javier, Gómez Gramuglio, Gervasio|||0000-0002-1077-6553, Rodrigo Anoro, Teresa, Ruiz Jimeno, Alberto|||0000-0002-3639-0368, Scodellaro, Luca|||0000-0002-4974-8330, Vila Álvarez, Iván |||0000-0002-6797-7209, Vilar Cortabitarte, Rocío|||0000-0003-2045-8054, Arisawa, Tetsuo, Adelman, Jahred
Tipo de recurso: artículo
Fecha de publicación:2009
País:España
Institución:Universidad de Cantabria (UC)
Repositorio:UCrea Repositorio Abierto de la Universidad de Cantabria
Idioma:inglés
OAI Identifier:oai:repositorio.unican.es:10902/2064
Acceso en línea:http://hdl.handle.net/10902/2064
Access Level:acceso abierto
Descripción
Sumario:We report the observation of the bottom, doubly-strange baryon Ωb- through the decay chain Ωb-→J/ψΩ-, where J/ψ→μ+μ-, Ω-→ΛK-, and Λ→pπ-, using 4.2  fb-1 of data from pp̅ collisions at √s=1.96  TeV, and recorded with the Collider Detector at Fermilab. A signal is observed whose probability of arising from a background fluctuation is 4.0×10-8, or 5.5 Gaussian standard deviations. The Ωb- mass is measured to be 6054.4±6.8(stat)±0.9(syst)  MeV/c2. The lifetime of the Ωb- baryon is measured to be 1.13-0.40+0.53(stat)±0.02(syst)  ps. In addition, for the Ξb- baryon we measure a mass of 5790.9±2.6(stat)±0.8(syst)  MeV/c2 and a lifetime of 1.56-0.25+0.27(stat)±0.02(syst)  ps. Under the assumption that the Ξb- and Ωb- are produced with similar kinematic distributions to the Λb0 baryon, we find σ(Ξb-)B(Ξb-→J/ψΞ-)/σ(Λb0)B(Λb0→J/ψΛ)=0.167-0.025+0.037(stat)±0.012(syst) and σ(Ωb-)B(Ωb-→J/ψΩ-)/σ(Λb0)B(Λb0→J/ψΛ)=0.045-0.012+0.017(stat)± 0.004(syst) for baryons produced with transverse momentum in the range of 6–20  GeV/c.

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