Study of η − η' mixing from measurement of B [subscript (s)] [superscript 0] → [J over ψη(')] decay rates

• Main Authors: Counts, Ian Thomas Hunt (Contributor), Ilten, Philip James (Contributor), Williams, M. (Contributor)
• Other Authors: Massachusetts Institute of Technology. Department of Physics (Contributor), Massachusetts Institute of Technology. Laboratory for Nuclear Science (Contributor)
• Format: Article
• Language: English
• Published: Springer-Verlag, 2015-02-18T16:26:14Z.
• Subjects: Article
• Online Access: Get fulltext

 A study of B and B[superscript s] meson decays into [J over ψ η] and [J over ψ η'] final states is performed using a data set of proton-proton collisions at centre-of-mass energies of 7 and 8 TeV, collected by the LCHb experiment and corresponding to 3.0 fb[superscript −1] of integrated luminosity. The decay B[superscript 0] → [J over ψ η'] is observed for the first time. The following ratios of branching fractions are measured: B(B[superscript 0] → [J over ψη']) [over B(B[superscript 0][subscript s] → [J over ψη'])] = (2.28±0.65 (stat) ±0.10 (syst) ±0.13 ([fs over fd])) ×10[superscript −2], B(B[superscript 0]→ [J over ψη]) [over B(B[superscript 0][subscript s] → [J over ψη])] = (1.85 ± 0.61 (stat) ± 0.09 (syst) ± 0.11 [(fs over fd)]) ×10[superscript −2], where the third uncertainty is related to the present knowledge of f[subscript s][ over fd], the ratio between the probabilities for a b quark to form a B[superscript s] or a B[superscript 0] meson. The branching fraction ratios are used to determine the parameters of η − η' meson mixing. In addition, the first evidence for the decay B[superscript s] → ψ(2S)η' is reported, and the relative branching fraction is measured, B(B[superscript 0][subscript s] → ψ(2S)η') [over B(B[superscript 0][subscript s] → [J over ψη'])] =(38.7 ± 9.0 (stat) ± 1.3 (syst) ± 0.9(B)) ×10[superscript −2], where the third uncertainty is due to the limited knowledge of the branching fractions of [J over ψ] and ψ(2S) mesons.