Measurement of fs/fu Variation with Proton-Proton Collision Energy and B-Meson Kinematics

The ratio of the B[superscript 0 over subscript s] and B[superscript +] fragmentation fractions f[subscript s] and f[subscript u] is studied with B[superscript 0 over subscript s]→J/ψϕ and B[superscript +]→J/ψK[superscript +] decays using data collected by the LHCb experiment in proton-proton collis...

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Bibliographic Details
Main Authors: LHCb Collaboration, Boettcher, T., Craik, D. C., Weisser, Constantin, Williams, M.
Other Authors: Massachusetts Institute of Technology. Department of Physics
Format: Article
Language:English
Published: American Physical Society 2020
Online Access:https://hdl.handle.net/1721.1/125904
Description
Summary:The ratio of the B[superscript 0 over subscript s] and B[superscript +] fragmentation fractions f[subscript s] and f[subscript u] is studied with B[superscript 0 over subscript s]→J/ψϕ and B[superscript +]→J/ψK[superscript +] decays using data collected by the LHCb experiment in proton-proton collisions at 7, 8, and 13 TeV center-of-mass energies. The analysis is performed in bins of B-meson momentum, longitudinal momentum, transverse momentum, pseudorapidity, and rapidity. The fragmentation-fraction ratio f[subscript s]/f[subscript u] is observed to depend on the B-meson transverse momentum with a significance of 6.0σ. This dependency is driven by the 13 TeV sample (8.7σ), while the results for the other collision energies are not significant when considered separately. Furthermore, the results show a 4.8σ evidence for an increase of f[subscript s]/f[subscript u] as a function of collision energy.