Λb polarization in Z 0 decays at LEP

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doi:10.1016/s0370-2693(99)01431-8

Abstract

The longitudinal polarization of the Λ b baryon is measured at the LEP e +e − collider by DELPHI. It is determined from the charged lepton and neutrino energy spectra in 249±19 Λ b semileptonic decays reconstructed in ≈3.5 million hadronic Z 0 decays using Λ 0-lepton correlations. The measured polarization is: P Λ b =−0.49 −0.30 +0.32(stat.)±0.17(syst.)

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