Observation of the {omega}{sub b}{sup -} baryon and measurement of the properties of the {xi}{sub b}{sup -} and {omega}{sub b}{sup -} baryons

Journal Article · Thu Oct 01 00:00:00 EDT 2009 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.80.072003· OSTI ID:21325196

Aaltonen, T; Maki, T; Mehtala, P; Orava, R; Osterberg, K; Saarikko, H; Remortel, N van ^[1]; Adelman, J; Brubaker, E; Fedorko, W T; Grosso-Pilcher, C; Ketchum, W; Kim, Y K; Krop, D; Kwang, S; Lee, H S; Paramonov, A A; Schmidt, M A; Shiraishi, S; Shochet, M ^[2]

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1. Division of High Energy Physics, Department of Physics, University of Helsinki and Helsinki Institute of Physics, FIN-00014, Helsinki (Finland)
2. Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637 (United States)

We report the observation of the bottom, doubly-strange baryon {omega}{sub b}{sup -} through the decay chain {omega}{sub b}{sup -}{yields}J/{psi}{omega}{sup -}, where J/{psi}{yields}{mu}{sup +}{mu}{sup -}, {omega}{sup -}{yields}{lambda}K{sup -}, and {lambda}{yields}p{pi}{sup -}, using 4.2 fb{sup -1} of data from pp collisions at {radical}(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 4.0x10{sup -8}, or 5.5 Gaussian standard deviations. The {omega}{sub b}{sup -} mass is measured to be 6054.4{+-}6.8(stat){+-}0.9(syst) MeV/c{sup 2}. The lifetime of the {omega}{sub b}{sup -} baryon is measured to be 1.13{sub -0.40}{sup +0.53}(stat){+-}0.02(syst) ps. In addition, for the {xi}{sub b}{sup -} baryon we measure a mass of 5790.9{+-}2.6(stat){+-}0.8(syst) MeV/c{sup 2} and a lifetime of 1.56{sub -0.25}{sup +0.27}(stat){+-}0.02(syst) ps. Under the assumption that the {xi}{sub b}{sup -} and {omega}{sub b}{sup -} are produced with similar kinematic distributions to the {lambda}{sub b}{sup 0} baryon, we find ({sigma}({xi}{sub b}{sup -})B({xi}{sub b}{sup -}{yields}J/{psi}{xi}{sup -})/{sigma}({lambda}{sub b}{sup 0})B({lambda}{sub b}{sup 0}{yields}J/{psi}{lambda}))=0.167{sub -0.025}{sup +0.037}(stat){+-}0.012(syst) and ({sigma}({omega}{sub b}{sup -})B({omega}{sub b}{sup -}{yields}J/{psi}{omega}{sup -})/{sigma}({lambda}{sub b}{sup 0})B({lambda}{sub b}{sup 0}{yields}J/{psi}{lambda}))=0.045{sub -0.012}{sup +0.017}(stat){+-} 0.004(syst) for baryons produced with transverse momentum in the range of 6-20 GeV/c.

• OSTI ID: 21325196
• Journal Information: Physical Review. D, Particles Fields, Vol. 80, Issue 7; Other Information: DOI: 10.1103/PhysRevD.80.072003; (c) 2009 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

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