Observation of the Omega [subscript b][superscript -] baryon and measurement of the properties of the Xi[subscript b][superscript -] and Omega [subscript b][superscript -] baryons

• Main Authors: Xie, Si (Contributor), Paus, Christoph M. E. (Contributor), Makhoul, K. (Contributor), Knuteson, Bruce O. (Contributor), Henderson, C. (Contributor), Hahn, Kristian Allan (Contributor), Goncharov, Maxim (Contributor), Gomez-Ceballos, Guillelmo (Contributor), Choudalakis, Georgios (Contributor), Bauer, Gerry P. (Contributor)
• Other Authors: Massachusetts Institute of Technology. Laboratory for Nuclear Science (Contributor), Paus, C. (Contributor)
• Format: Article
• Language: English
• Published: American Physical Society, 2010-03-18T16:27:42Z.
• Subjects: Article
• Online Access: Get fulltext

We report the observation of the bottom, doubly-strange baryon Ω[subscript b][superscript -] through the decay chain Ω[subscript b][superscript -]→J/ψΩ[superscript -], where J/ψ→μ[superscript +]μ[superscript -], Ω[superscript -]→ΛK[superscript -], and Λ→pπ[superscript -], using 4.2  fb[superscript -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[superscript -8], or 5.5 Gaussian standard deviations. The Ω[subscript b][superscript -] mass is measured to be 6054.4±6.8(stat)±0.9(syst)   MeV/c[superscript 2]. The lifetime of the Ω[subscript b][superscript -] baryon is measured to be 1.13[subscript -0.40][superscript +0.53](stat)±0.02(syst)  ps. In addition, for the Ξ[subscript b][superscript -] baryon we measure a mass of 5790.9±2.6(stat)±0.8(syst)  MeV/c[superscript 2] and a lifetime of 1.56[subscript -0.25][superscript +0.27](stat)±0.02(syst)  ps. Under the assumption that the Ξ[subscript b][superscript -] and Ω[subscript b][superscript -] are produced with similar kinematic distributions to the Λ[subscript b][superscript 0] baryon, we find σ(Ξ[subscript b][superscript -])B(Ξ[subscript b][superscript -]→J/ψΞ[superscript ]-)/σ(Λ[subscript b][superscript 0])B(Λ[subscript b][superscript 0]→J/ψΛ)=0.167[subscript -0.025][superscript +0.037](stat)±0.012(syst) and σ(Ω[subscript b][superscript -])B(Ω[subscript b][superscript -]→J/ψΩ[superscript -])/σ(Λ[subscript b][superscript -])B(Λ[subscript b][superscript -]→J/ψΛ)=0.045[subscript -0.012][superscript +0.017](stat)± 0.004(syst) for baryons produced with transverse momentum in the range of 6-20  GeV/c.
Academy of Finland
Slovak R&D Agency
Programa Consolider-Ingenio 2010, Spain
Ministerio de Ciencia e Innovación, Spain
Russian Foundation for Basic Research
Institut National de Physique Nucleaire et Physique des Particules/CNRS
Science and Technology Facilities Council and the Royal Society, UK
Korean Research Foundation
Korean Science and Engineering Foundation
Bundesministerium für Bildung und Forschung, Germany
Alfred P. Sloan Foundation
Swiss National Science Foundation
National Science Council of the Republic of China
Natural Sciences and Engineering Research Council of Canada
Ministry of Education, Culture, Sports, Science and Technology of Japan
Italian Istituto Nazionale di Fisica Nucleare
National Science Foundation
United States Department of Energy