Study of $\eta -{\eta }^{\prime }$ mixing from measurement of $B_{(s)}^0\to J/\psi {\eta }^{(\prime )}$~decay rates

Abstract

A study of $B^0$~and $B_s^0$ meson decays into $J/\psi \eta$~and $J/\psi {\eta }^{\prime }$ final states is performed using a data set of proton-proton collisions at centre-of-mass energies of 7 and 8TeV, collected by the LHCb experiment and corresponding to 3.0fb${}^{-1}$ of integrated luminosity. The decay $B^0\to J/\psi {\eta }^{\prime }$ is observed for thefirst time. The following ratios of branching fractions are measured: $$\frac{\mathcal{B}(B^0\to J/\psi {\eta }^{\prime })}{\mathcal{B}(B_s^0\to J/\psi {\eta }^{\prime })}=(2.28\pm 0.65(stat)\pm 0.10(syst)\pm 0.13(f_s/f_d))\times 10^{-2},$$ $$\frac{\mathcal{B}(B^0\to J/\psi \eta )}{\mathcal{B}(B_s^0\to J/\psi \eta )}=(1.85\pm 0.61(stat)\pm 0.09(syst)\pm 0.11(f_s/f_d))\times 10^{-2},$$ where the third uncertainty is related to the present knowledge of $f_s/f_d$, the ratio between the probabilities for a $b$ quark to form a $B_s^0$ or $B^0$ meson. The branching fraction ratios are used to determine the parameters of $\eta -{\eta }^{\prime }$ meson mixing. In addition, the first evidence for the decay $B_s^0\to \psi (2S){\eta }^{\prime }$ is reported, and the relative branching fraction is measured, $$\frac{\mathcal{B}(B_s^0\to \psi (2S){\eta }^{\prime })}{\mathcal{B}(B_s^0\to J/\psi {\eta }^{\prime })}=(38.7\pm 9.0(stat)\pm 1.3(syst)\pm 0.9(\mathcal{B}))\times 10^{-2},$$ where the third uncertainty is due to the limited knowledge of the branching fractions of $J/\psi$ and $\psi (2S)$~mesons.

26 pages, 7 figures

References in corpus (9)

• PYTHIA 6.4 Physics and Manual
• Big-Bang Nucleosynthesis
• Performance of the LHCb Vertex Locator
• Branching Ratio Measurements of $B_s$ Decays
• A global fit to determine the pseudoscalar mixing angle and the gluonium content of the eta' meson
• Composition of the Pseudoscalar Eta and Eta' Mesons
• Measurement of the ratio of prompt ${\chi }_c$ to $J/\psi$ production in $pp$ collisions at $\sqrt{s}=7$ TeV
• Nonleptonic $B_s$ to charmonium decays: analyses in pursuit of determining the weak phase ${\beta }_s$
• Relative rates of B meson decays into psi(2S) and J/psi mesons

Cited by in corpus (11)

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• Measurement of the Dynamics of the Decays $D_s^{+}\to {\eta }^{(\prime )}{e}^{+}{\nu }_e$
• Precision Measurements of $D_s^{+}\to \eta e^{+}{\nu }_e$ and $D_s^{+}\to {\eta }^{\prime }{e}^{+}{\nu }_e$
• Measurement of the $B_s^0\to J/\psi \eta$ lifetime
• Study of charmonium and charmonium-like contributions in $B^{+}\to J/\psi \eta K^{+}$ decays
• Mixing effects of $\eta -{\eta }^{\prime }$ in ${\Lambda }_b\to \Lambda {\eta }^{{(}^{\prime })}$ decays
• Contributions of $\rho (770,1450)\to \omega \pi$ for the Cabibbo-favored $D\to h\omega \pi$ decays
• Contributions of the subprocess $K_0^{\ast }(1430)\to K{\eta }^{\prime }$ in the charmless three-body $B$ meson decays
• CP violation in quasi-two-body $D\to VP$ decays and three-body $D$ decays mediated by vector resonances