Observation of the decay $B_s^0\to J/ψη$ and Evidence for $B_s^0\to J/ψη'$

Abstract

We report the first observation of $B_s^0\to J/ψη$ and evidence for $B_s^0\to J/ψη'$. These results are obtained from $23.6 \mathrm{fb}^{-1}$ of data collected at the $Υ(5S)$ resonance with the Belle detector at the KEKB $e^+e^-$ collider. We measure the branching fractions $\mathcal{B}(B_s^0\to J/ψη)= (3.32 \pm 0.87(\mathrm{stat.})^{+0.32}_{-0.28}(\mathrm{syst.}) \pm 0.42(f_s))\times 10^{-4}}$ with a significance of $7.3 σ$, and $\mathcal{B}(B_s^0\to J/ψη')= (3.1 \pm 1.2(\mathrm{stat.})^{+0.5}_{-0.6}(\mathrm{syst.}) \pm 0.38(f_s))\times 10^{-4}$ with a significance of $3.8 σ$.

6 pages, 3 figures, 2 tables. Contributed to Moriond QCD 09, FPCP 09, EPS HEP 09, DPF 09, and BEAUTY 09