TY - JOUR
T1 - Measurement of the branching ratio Γ(Λb 0→ψ(2S)Λ0)/Γ(Λb 0→J/ψΛ0) with the ATLAS detector
AU - ATLAS Collaboration
AU - Aad, G.
AU - Abbott, B.
AU - Abdallah, J.
AU - Abdinov, O.
AU - Aben, R.
AU - Abolins, M.
AU - AbouZeid, O. S.
AU - Abramowicz, H.
AU - Abreu, H.
AU - Abreu, R.
AU - Abulaiti, Y.
AU - Acharya, B. S.
AU - Adamczyk, L.
AU - Adams, D. L.
AU - Adelman, J.
AU - Adomeit, S.
AU - Adye, T.
AU - Affolder, A. A.
AU - Agatonovic-Jovin, T.
AU - Agricola, J.
AU - Aguilar-Saavedra, J. A.
AU - Ahlen, S. P.
AU - Ahmadov, F.
AU - Aielli, G.
AU - Akerstedt, H.
AU - Åkesson, T. P.A.
AU - Akimov, A. V.
AU - Alberghi, G. L.
AU - Albert, J.
AU - Albrand, S.
AU - Alconada Verzini, M. J.
AU - Aleksa, M.
AU - Aleksandrov, I. N.
AU - Alexa, C.
AU - Alexander, G.
AU - Alexopoulos, T.
AU - Alhroob, M.
AU - Alimonti, G.
AU - Alio, L.
AU - Alison, J.
AU - Alkire, S. P.
AU - Allbrooke, B. M.M.
AU - Allport, P. P.
AU - Aloisio, A.
AU - Alonso, A.
AU - Alonso, F.
AU - Alpigiani, C.
AU - Altheimer, A.
AU - Alvarez Gonzalez, B.
AU - Cottin, G.
N1 - Funding Information:
We acknowledge the support of ANPCyT , Argentina; YerPhI , Armenia; ARC , Australia; BMWFW and FWF , Austria; ANAS , Azerbaijan; SSTC , Belarus; CNPq and FAPESP , Brazil; NSERC , NRC and CFI , Canada; CERN ; CONICYT , Chile; CAS , MOST and NSFC , China; COLCIENCIAS , Colombia; MSMT CR , MPO CR and VSC CR, Czech Republic; DNRF , DNSRC and Lundbeck Foundation , Denmark; EPLANET , ERC and NSRF , European Union ; IN2P3-CNRS , CEA-DSM/IRFU , France; GNSF , Georgia; BMBF , DFG , HGF , MPG and AvH Foundation , Germany; GSRT and NSRF , Greece; RGC , Hong Kong SAR , China; ISF , MINERVA , GIF , I-CORE and Benoziyo Center , Israel; INFN , Italy; MEXT and JSPS , Japan; CNRST , Morocco; FOM and NWO , Netherlands; BRF and RCN , Norway; MNiSW and NCN , Poland; GRICES and FCT , Portugal; MNE/IFA , Romania; MES of Russia and NRC KI , Russian Federation; JINR ; MSTD , Serbia; MSSR , Slovakia; ARRS and MIZŠ , Slovenia; DST/NRF , South Africa; MINECO , Spain; SRC and Wallenberg Foundation , Sweden; SER , SNSF and Cantons of Bern and Geneva , Switzerland; NSC , Taiwan; TAEK , Turkey; STFC , the Royal Society and Leverhulme Trust , United Kingdom; DOE and NSF , United States of America.
Funding Information:
The crucial computing support from all WLCG partners is acknowledged gratefully, in particular from CERN and the ATLAS Tier-1 facilities at TRIUMF (Canada), NDGF (Denmark, Norway, Sweden), CC-IN2P3 (France), KIT/GridKA (Germany), INFN-CNAF (Italy), NL-T1 (Netherlands), PIC (Spain), ASGC (Taiwan), RAL (UK) and BNL (USA) and in the Tier-2 facilities worldwide.
Publisher Copyright:
© 2015 CERN for the benefit of the ATLAS Collaboration
PY - 2015/12/17
Y1 - 2015/12/17
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=85042517730&partnerID=8YFLogxK
U2 - 10.1016/j.physletb.2015.10.009
DO - 10.1016/j.physletb.2015.10.009
M3 - Article
AN - SCOPUS:85042517730
SN - 0370-2693
VL - 751
SP - 63
EP - 80
JO - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
JF - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
ER -