# Observation of the decay $B_s^0 \to \eta_c^\phi$ and evidence for $B_s^0 \to \eta_c\pi^+\pi^-$

LHCb Collaboration; Bernet, R; Müller, K; Serra, N; Steinkamp, O; Straumann, U; Vollhardt, A; et al (2017). Observation of the decay $B_s^0 \to \eta_c^\phi$ and evidence for $B_s^0 \to \eta_c\pi^+\pi^-$. Journal of High Energy Physics, 07:021.

## Abstract

A study of $B_s^0 \to \eta_c\phi$ and $B^0_s \to \eta_c \pi^+\pi^-$ decays is performed using pp collision data corresponding to an integrated luminosity of 3.0 fb$^{−1}$, collected with the LHCb detector in Run 1 of the LHC. The observation of the decay $B_s^0 \to \eta_c\phi$ is reported, where the $\eta_c$ meson is reconstructed in the $p\overline{p}, K^+K^-\pi^+\pi^-, \pi^+\pi^-\pi^+\pi^-$ and $K^+K^-K^+K^-$ decay modes and the $\phi(1020)$ in the $K^+K^-$ decay mode. The decay $B_s^0 \to J/\psi\phi$ is used as a normalisation channel. Evidence is also reported for the decay $B_s^0 \to \eta_c\pi^+\pi^-$, where the $\eta_c$ meson is reconstructed in the $p\overline{p}$ decay mode, using the decay $B_s^0 \to J/\psi\pi^+\pi^-$ as a normalisation channel. The measured branching fractions are
$\mathcal{B}(B^0_s \to \eta_c\phi) = (5.01 \pm 0.53 \pm 0.27 \pm 0.63) \times 10^{−4}$,
$\mathcal{B}(B^0_s \to \eta_c\pi^+\pi^−) = (1.76 \pm 0.59 \pm 0.12 \pm 0.29) \times 10$^{−4}$, where in each case the first uncertainty is statistical, the second systematic and the third uncertainty is due to the limited knowledge of the external branching fractions. ## Abstract A study of$B_s^0 \to \eta_c\phi$and$B^0_s \to \eta_c \pi^+\pi^-$decays is performed using pp collision data corresponding to an integrated luminosity of 3.0 fb$^{−1}$, collected with the LHCb detector in Run 1 of the LHC. The observation of the decay$B_s^0 \to \eta_c\phi$is reported, where the$\eta_c$meson is reconstructed in the$p\overline{p}, K^+K^-\pi^+\pi^-, \pi^+\pi^-\pi^+\pi^-$and$K^+K^-K^+K^-$decay modes and the$\phi(1020)$in the$K^+K^-$decay mode. The decay$B_s^0 \to J/\psi\phi$is used as a normalisation channel. Evidence is also reported for the decay$B_s^0 \to \eta_c\pi^+\pi^-$, where the$\eta_c$meson is reconstructed in the$p\overline{p}$decay mode, using the decay$B_s^0 \to J/\psi\pi^+\pi^-$as a normalisation channel. The measured branching fractions are$\mathcal{B}(B^0_s \to \eta_c\phi) = (5.01 \pm 0.53 \pm 0.27 \pm 0.63) \times 10^{−4}$,$\mathcal{B}(B^0_s \to \eta_c\pi^+\pi^−) = (1.76 \pm 0.59 \pm 0.12 \pm 0.29) \times 10$^{−4}$,
where in each case the first uncertainty is statistical, the second systematic and the third uncertainty is due to the limited knowledge of the external branching fractions.

## Statistics

### Citations

Dimensions.ai Metrics
3 citations in Web of Science®
5 citations in Scopus®

### Altmetrics

Detailed statistics

Item Type: Journal Article, refereed, original work 07 Faculty of Science > Physics Institute 530 Physics English 2017 08 Feb 2018 10:23 19 Feb 2018 10:45 Springer 1029-8479 Gold Publisher DOI. An embargo period may apply. https://doi.org/10.1007/JHEP07(2017)021

Preview
Content: Published Version
Filetype: PDF
Size: 1MB
View at publisher
Licence: