Study of the B[subscript c][superscript +] → J/ψD[subscript s][superscript +] and B[subscript c][superscript +] → J/ψD[subscript s][superscript *+] decays with the ATLAS detector
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Taylor, Frank E
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Study of the B+c→J/ψD+ and B+c→J/ψD∗+ decays with the ATLAS detector
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The decays B[subscript c][superscript +] → J/ψD[subscript s][superscript +] and B[subscript c][superscript +] → J/ψD[subscript s][superscript *+] are studied with the ATLAS detector at the LHC using a dataset corresponding to integrated luminosities of 4.9 and 20.6 fb[superscript −1] of pp collisions collected at centre-of-mass energies √s= 7 TeV and 8 TeV, respectively. Signal candidates are identified through J/ψ→μ[superscript +]μ[superscript −] and D[superscript (∗)+][subscript s]→ϕπ[superscript +](γπ[superscript 0]) decays. With a two-dimensional likelihood fit involving the B[superscript +][subscript c] reconstructed invariant mass and an angle between the μ[superscript +] and D[superscript +][subscript s] candidate momenta in the muon pair rest frame, the yields of B[superscript +][subscript c]→J/ψD[superscript +][subscript s] and B[superscript +][subscript c]→J/ψD[superscript ∗+][subscript s], and the transverse polarisation fraction in B[superscript +][subscript c]→J/ψD[superscript ∗+][subscript s] decay are measured. The transverse polarisation fraction is determined to be Γ[subscript ±±](B[superscript +][subscript c] → J/ψD[superscript ∗+][subscript s])/Γ(B[superscript +][subscript c] → J/ψD[superscript ∗+][subscript s]) = 0.38±0.23±0.07, and the derived ratio of the branching fractions of the two modes is B[subscript B[superscript +][subscript c]→J/ψD[superscript ∗+][superscript s]]/B[subscript B[superscript +][subscript c]→J/ψD[superscript +][subscript s]]=2.8+1.2−0.8±0.3, where the first error is statistical and the second is systematic. Finally, a sample of B[superscript +][subscript c]→J/ψπ[superscript +] decays is used to derive the ratios of branching fractions B[subscript B[superscript +][subscript c]→J/ψD[superscript +][subscript s]]/B[subscript B[superscript +]c→J/ψπ[superscript +]]=3.8±1.1±0.4±0.2 and B[subscript B[superscript +][subscript c]→J/ψD[superscript ∗+][subscript s]]/B[subscript B[superscript +][superscript c]→J/ψπ[superscript +]]=10.4±3.1±1.5±0.6, where the third error corresponds to the uncertainty of the branching fraction of D[superscript +][subscript s]→ϕ(K[superscript +]K[superscript −])π[superscript +] decay. The available theoretical predictions are generally consistent with the measurement.
Date issued
2016-01Department
Massachusetts Institute of Technology. Department of PhysicsJournal
European Physical Journal C
Publisher
Springer-Verlag
Citation
Aad, G., B. Abbott, J. Abdallah, O. Abdinov, R. Aben, M. Abolins, O. S. AbouZeid, et al. "Study of the B[subscript c][superscript +] → J/ψD[subscript s][superscript +] and B[subscript c][superscript +] → J/ψD[subscript s][superscript *+] decays with the ATLAS detector.” The European Physical Journal C 76, no. 1 (January 2016). © 2015 CERN for the benefit of the ATLAS collaboration
Version: Final published version
ISSN
1434-6044
1434-6052