1202.0103 (Jin Li et al.)

First observations of $B_s^0\to J/ψη$ and $B_s^0\to J/ψη'$    [PDF]

Jin Li, for the Belle Collaboration

We report first observations of $B_s^0\to J/\psi\eta$ and $B_s^0\to
J/\psi\eta'$. The results are obtained from 121.4 fb^{-1} of data collected at
the $\Upsilon(5S)$ resonance with the Belle detector at the KEKB $e^+e^-$
collider. We obtain the branching fractions Br(B_s^0\to J/\psi\eta)= (5.10\pm
0.50(stat.)\pm 0.25(syst.)^{+1.14}_{-0.79}(N_{B_s^(*)\bar B_s^(*))) \times
10^{-4}, and Br(B_s^0\to J/\psi\eta')=(3.71\pm 0.61(stat.)\pm
0.18(syst.)^{+0.83}_{-0.57}(N_{B_s^(*)\bar B_s^(*))) \times 10^{-4}. The ratio
of the two branching fractions is measured to be $\frac{Br(B_s\to
J/\psi\eta')}{Br(B_s\to J/\psi \eta)} = 0.73\pm 0.14(stat.)\pm 0.02(syst.)$.

View original: http://arxiv.org/abs/1202.0103