Collaboration, D;
Abazov, V;
(2007)
Direct observation of the strange b baryon Xi_b^{-}.
Phys.Rev.Lett.
, 99
(5)
, Article 052001. 10.1103/PhysRevLett.99.052001.
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Abstract
We report the first direct observation of the strange b baryon Xi_b^{-}. We reconstruct the decay Xi_b^{-} to J/psi Xi^{-}, with J/psi to dimuons and Xi^{-} to Lambda pion, in ppbar collisions at sqrt(s) = 1.96 TeV. Using 1.3 fb^{-1} of data collected by the D0 detector, we observe 15.2 +/- 4.4(stat.)+ 1.9/-0.4(syst.) Xi_b^{-} candidates at a mass of 5.774 +/- 0.011(stat.) +/- 0.015 (syst.) GeV. The significance of the observed signal is 5.5 sigmas, equivalent to a probability of 3.3 X 10^{-8} of it arising from a background fluctuation. Normalizing to the decay Lambda_b to J/psi Lambda, we measure the relative rate to be 0.28 +/- 0.09(stat.)+ 0.09/-0.08 (syst.).
Type: | Article |
---|---|
Title: | Direct observation of the strange b baryon Xi_b^{-} |
Open access status: | An open access version is available from UCL Discovery |
DOI: | 10.1103/PhysRevLett.99.052001 |
Publisher version: | http://dx.doi.org/10.1103/PhysRevLett.99.052001 |
Language: | English |
Additional information: | © 2007 The American Physical Society |
UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
URI: | https://discovery.ucl.ac.uk/id/eprint/1374364 |
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