Measurement of $B^0\to J/\psi {\eta }^{(}{}^{\prime }{}^{)}$ and Constraint on the $\eta -{\eta }^{\prime }$ Mixing Angle

M. -C. Chang, Y. -C. Duh, J. -Y. Lin +153

We measure the branching fractions of $B^0\to J/\psi {\eta }^{(}{}^{\prime }{}^{)}$ decays with the complete Belle data sample of $772\times 10^6$ $B\bar{B}$ events collected at the ${\rm Y}(4S)$ res…