$B^0\to \omega {\eta }^{(\prime )}$ and $\varphi {\eta }^{(\prime )}$ decays in the perturbative QCD approach

Abstract

We calculate the branching ratios and CP-violating asymmetries for $B^0\to \omega \eta$, $\omega {\eta }^{\prime }$, $\varphi \eta$ and $\varphi {\eta }^{\prime }$ decays in the perturbative QCD (pQCD) factorization approach. The pQCD predictions for the CP-averaged branching ratios are Br(B^0 \to \omega\eta) = \left (2.7 ^{+1.1}_{-1.0})\times 10^{-7}, Br(B^0 \to \omega \eta^\prime) = \left (0.75 ^{+0.37}_{-0.33}) \times 10^{-7}, and Br(B^0 \to \phi\eta) = \left (6.3 ^{+3.3}_{-1.9}) \times 10^{-9}, Br(B^0 \to \phi\eta^{\prime}) = \left (7.3^{+3.5}_{-2.6}) \times 10^{-9} which are consistent with currently available experimental upper limits. The inclusion of the gluonic contribution can change the branching ratios of $B\to \omega (\varphi ){\eta }^{\prime }$ decays by about 10%. The direct CP-violating asymmetries for $B^0\to \omega \eta$ and $\omega {\eta }^{\prime }$ decays are generally large in size.

Comments: 23 pages, 4 ps/eps figures, RevTex, typos removed, minor corrections