Publikace na Matematicko-fyzikální fakulta |
2012
Abstrakt
We measure the branching fractions of B-0 -> J/psi eta((')) decays with the complete Belle data sample of 772 x 10(6) B (B) over bar events collected at the Y(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. The results for the branching fractions are: B(B-0 -> J/psi eta) = (12.3 +/-(1.8)(1.7)+/- 0.7) x 10(-6) and B(B-0 -> J/psi eta') < 7.4 x 10(-6) at 90% confidence level.
The eta-eta' mixing angle is constrained to be less than 42.2 degrees at 90% confidence level.