Measurement of the parity-violating asymmetry parameter αb and the helicity amplitudes for the decay Λb0 →j /ψ Λ0 with the ATLAS detector

Atlas Collaboration

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A measurement of the parity-violating decay asymmetry parameter, αb, and the helicity amplitudes for the decay Λb0→J/ψ(μ+μ-)Λ0(pπ-) is reported. The analysis is based on 1400 Λb0 and Λ¯b0 baryons selected in 4.6 fb-1 of proton-proton collision data with a center-of-mass energy of 7 TeV recorded by the ATLAS experiment at the LHC. By combining the Λb0 and Λ¯b0 samples under the assumption of CP conservation, the value of αb is measured to be 0.30±0.16(stat)±0.06(syst). This measurement provides a test of theoretical models based on perturbative QCD or heavy-quark effective theory.

Original languageEnglish
Article number092009
JournalPhysical Review D - Particles, Fields, Gravitation and Cosmology
Issue number9
Publication statusPublished - May 27 2014


All Science Journal Classification (ASJC) codes

  • Nuclear and High Energy Physics
  • Physics and Astronomy (miscellaneous)

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