Study of $η-η^\prime$ mixing from measurement of $B^0_(s) \rightarrow J/ψ η^(\prime)$ decay ratesстатья
Статья опубликована в высокорейтинговом журнале
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Дата последнего поиска статьи во внешних источниках: 29 февраля 2016 г.
Аннотация:
A study of B0 and B0s meson decays into J/ψη and J/ψη′ 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 LHCb experiment and corresponding to 3.0fb−1 of integrated luminosity. The decay B0→J/ψη′ is observed for the first time. The following ratios of branching fractions are measured:
B(B0→J/ψη′)B(B0s→J/ψη′)B(B0→J/ψη)B(B0s→J/ψη)==(2.28±0.65(stat)±0.10(syst)±0.13(fs/fd))×10−2,(1.85±0.61(stat)±0.09(syst)±0.11(fs/fd))×10−2,
where the third uncertainty is related to the present knowledge of fs/fd, the ratio between the probabilities for a b quark to form a B0s or a B0 meson. The branching fraction ratios are used to determine the parameters of η−η′ meson mixing. In addition, the first evidence for the decay B0s→ψ(2S)η′ is reported, and the relative branching fraction is measured,
B(B0s→ψ(2S)η′)B(B0s→J/ψη′)=(38.7±9.0(stat)±1.3(syst)±0.9(B))×10−2,
where the third uncertainty is due to the limited knowledge of the branching fractions of J/ψ and ψ(2S) mesons.