Measurement of the branching ratio ᴦ( ᴧ0b→ψ(2S) ᴧ0)/ ᴦ(ᴧ0b→J/ψ ᴧ0) with the ATLAS detector Aad, G. Aguilar Saavedra, Juan Antonio Atlas Collaboration ATLAS detector Proton–proton collisions Branching processes An observation of the Lambda(0)(b) -> Psi (2S) Lambda(0) decay and a comparison of its branching fraction with that of the Lambda(0)(b) -> Psi (2S) Lambda(0) decay has been made with the ATLAS detector in proton-proton collisions at root s = 8 TeVat the LHC using an integrated luminosity of 20.6fb(-1). The J/Psi and Psi(2S) mesons are reconstructed in their decays to a muon pair, while the Lambda(0) -> p pi(-) decay is exploited for the Lambda(0) 0baryon reconstruction. The Lambda(0)(b) baryons are reconstructed with transverse momentum p(T)> 10 GeVand pseudorapidity vertical bar eta vertical bar < 2.1. The measured branching ratio of the Lambda(0)(b) -> Psi (2S) Lambda(0) and Lambda(0)(b) -> Psi (2S) Lambda(0) decays is Gamma(Lambda(0)(b) -> Psi (2S) Lambda(0)) / Gamma(Lambda(0)(b) -> Psi (2S) Lambda(0)) = 0.501 +/- 0.033(stat) +/- 0.019(syst), lower than the expectation from the covariant quark model. 2018-02-07T12:09:06Z 2018-02-07T12:09:06Z 2015-12-17 info:eu-repo/semantics/article Atlas Collaboration. Measurement of the branching ratio ᴦ( ᴧ0b→ψ(2S) ᴧ0)/ ᴦ(ᴧ0b→J/ψ ᴧ0) with the ATLAS detector. Physics Letters B, 751: 63-80 (2015). [http://hdl.handle.net/10481/49372] 0370-2693 1873-2445 http://hdl.handle.net/10481/49372 10.1016/j.physletb.2015.10.009 eng http://creativecommons.org/licenses/by-nc-nd/3.0/ info:eu-repo/semantics/openAccess Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License Elsevier