@article{af16db7b093449c4ae49218a40795fee,
title = "Measurement of the branching ratio Γ(Λb 0→ψ(2S)Λ0)/Γ(Λb 0→J/ψΛ0) with the ATLAS detector",
abstract = "An observation of the Λb 0→ψ(2S)Λ0 decay and a comparison of its branching fraction with that of the Λb 0→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 Λb 0 baryons are reconstructed with transverse momentum pT>10 GeV and pseudorapidity |η|<2.1. The measured branching ratio of the Λb 0→ψ(2S)Λ0 and Λb 0→J/ψΛ0 decays is Γ(Λb 0→ψ(2S)Λ0)/Γ(Λb 0→J/ψΛ0)=0.501±0.033(stat)±0.019(syst), lower than the expectation from the covariant quark model.",
author = "{ATLAS Collaboration} and G. Aad and B. Abbott and J. Abdallah and O. Abdinov and R. Aben and M. Abolins and AbouZeid, {O. S.} and H. Abramowicz and H. Abreu and R. Abreu and Y. Abulaiti and Acharya, {B. S.} and L. Adamczyk and Adams, {D. L.} and J. Adelman and S. Adomeit and T. Adye and Affolder, {A. A.} and T. Agatonovic-Jovin and J. Agricola and Aguilar-Saavedra, {J. A.} and Ahlen, {S. P.} and F. Ahmadov and G. Aielli and H. Akerstedt and {\AA}kesson, {T. P.A.} and Akimov, {A. V.} and Alberghi, {G. L.} and J. Albert and S. Albrand and {Alconada Verzini}, {M. J.} and M. Aleksa and Aleksandrov, {I. N.} and C. Alexa and G. Alexander and T. Alexopoulos and M. Alhroob and G. Alimonti and L. Alio and J. Alison and Alkire, {S. P.} and Allbrooke, {B. M.M.} and Allport, {P. P.} and A. Aloisio and A. Alonso and F. Alonso and C. Alpigiani and A. Altheimer and {Alvarez Gonzalez}, B. and G. Cottin",
note = "Publisher Copyright: {\textcopyright} 2015 CERN for the benefit of the ATLAS Collaboration",
year = "2015",
month = dec,
day = "17",
doi = "10.1016/j.physletb.2015.10.009",
language = "English",
volume = "751",
pages = "63--80",
journal = "Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics",
issn = "0370-2693",
publisher = "Elsevier B.V.",
}