Direct observation of the strange b Baryon Ξb

Authors

V. M. Abazov, Joint Institute for Nuclear Research, DubnaFollow
B. Abbott, University of Oklahoma
M. Abolins, Michigan State UniversityFollow
B. S. Acharya, Tata Institute of Fundamental Research, Mumbai
M. Adams, University of Illinois at ChicagoFollow
T. Adams, Florida State UniversityFollow
E. Aguilo, University of Alberta
S. H. Ahn, Korea UniversityFollow
Abaz Kryemadhi, Messiah UniversityFollow
G. D. Alexeev, Joint Institute for Nuclear Research, DubnaFollow

Document Type

Article

Publication Date

8-3-2007

Abstract

We report the first direct observation of the strange b baryon Ξb-(Ξ̄b+). We reconstruct the decay Ξb-→J/ψΞ-, with J/ψ→μ+μ-, and Ξ-→Λπ-→pπ-π- in pp̄ collisions at s=1.96TeV. Using 1.3fb-1 of data collected by the D0 detector, we observe 15.2±4.4(stat)-0.4+1.9(syst) Ξb- candidates at a mass of 5.774±0.011(stat)±0.015(syst)GeV. The significance of the observed signal is 5.5σ, equivalent to a probability of 3.3×10-8 of it arising from a background fluctuation. Normalizing to the decay Λb→J/ψΛ, we measure the relative rate σ(Ξb-)×B(Ξb-→J/ψΞ-)σ(Λb) ×B(Λb→J/ψΛ)=0.28±0.09(stat)-0.08+0.09(syst). © 2007 The American Physical Society.

Recommended Citation

Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T.; Aguilo, E.; Ahn, S. H.; Kryemadhi, Abaz; and Alexeev, G. D., "Direct observation of the strange b Baryon Ξb" (2007). Educator Scholarship & Departmental Newsletters. 147.
https://mosaic.messiah.edu/mps_ed/147