Measurement of the branching ratio Γ(Λb0→ψ(2S)Λ0)/Γ(Λb0→J/ψΛ0) with the ATLAS detector

Barton, Adam and Beattie, Michael and Borissov, Guennadi and Bouhova-Thacker, Evelina Vassileva and Dearnaley, William and Fox, Harald and Grimm, Kathryn Ann Tschann and Henderson, Robert Charles William and Hughes, Gareth and Jones, Roger William Lewis and Kartvelishvili, Vakhtang and Long, Robin Eamonn and Love, Peter Allan and Maddocks, Harvey and Skinner, Malcolm and Smizanska, Maria and Walder, James William and Wharton, Andy (2015) Measurement of the branching ratio Γ(Λb0→ψ(2S)Λ0)/Γ(Λb0→J/ψΛ0) with the ATLAS detector. Physics Letters B, 751. pp. 63-80. ISSN 0370-2693

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An observation of the Λb0→ψ(2S)Λ0 decay and a comparison of its branching fraction with that of the Λb0→J/ψΛ0 decay has been made with the ATLAS detector in proton–proton collisions at s=8 TeV at the LHC using an integrated luminosity of 20.6 fb −1 . The J/ψ and ψ(2S) mesons are reconstructed in their decays to a muon pair, while the Λ0→pπ− decay is exploited for the Λ0 baryon reconstruction. The Λb0 baryons are reconstructed with transverse momentum pT>10 GeV and pseudorapidity |η|<2.1 . The measured branching ratio of the Λb0→ψ(2S)Λ0 and Λb0→J/ψΛ0 decays is Γ(Λb0→ψ(2S)Λ0)/Γ(Λb0→J/ψΛ0)=0.501±0.033(stat)±0.019(syst) , lower than the expectation from the covariant quark model.

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Journal Article
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Physics Letters B
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29 Jan 2016 11:20
Last Modified:
11 Aug 2020 01:20