Measurement of the Λb polarization and angular parameters in Λb →j /ψ Λ decays from pp collisions at √s=7 and 8 TeV

CMS Collaboration

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An analysis of the bottom baryon decay Λb→J/ψ(→μ+μ-)Λ(→pπ-) is performed to measure the Λb polarization and three angular parameters in data from pp collisions at s=7 and 8 TeV, collected by the CMS experiment at the Large Hadron Collider. The Λb polarization is measured to be 0.00±0.06(stat)±0.06(syst) and the parity-violating asymmetry parameter is determined to be 0.14±0.14(stat)±0.10(syst). The measurements are compared to various theoretical predictions, including those from perturbative quantum chromodynamics.
Original languageEnglish
Article number072010
Number of pages20
JournalPhysical Review D
Issue number7
Publication statusPublished - 2018
Externally publishedYes

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