Evidence for the Decay X(3872) → ψ(2S)γ
Author(s)Counts, Ian Thomas Hunt; Ilten, Philip James; Williams, Michael
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Evidence for the decay mode X(3872) → ψ(2S)γ in B[superscript +] → X(3872)K[superscript +] decays is found with a significance of 4.4 standard deviations. The analysis is based on a data sample of proton–proton collisions, corresponding to an integrated luminosity of 3 fb[superscript −1], collected with the LHCb detector, at centre-of-mass energies of 7 and 8 TeV. The ratio of the branching fraction of the X(3872) →ψ (2S)γ decay to that of the X(3872) → J/ψγ decay is measured to be [B(X(3872) → ψ(2S)γ) over B(X(3872)→J/ψγ)] = 2.46 ± 0.64 ± 0.29, where the first uncertainty is statistical and the second is systematic. The measured value does not support a pure D[bar over D]⁎ molecular interpretation of the X(3872) state.
DepartmentMassachusetts Institute of Technology. Department of Physics; Massachusetts Institute of Technology. Laboratory for Nuclear Science
Nuclear Physics B
Aaij, R., et al. “Evidence for the Decay X(3872) → ψ(2S)γ.” Nuclear Physics B 886 (September 2014): 665–680. © 2014 CERN for the benefit of the LHCb Collaboration
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