Decays B_(s)rightarrow J/psi+η and B_(s)rightarrow J/psi+η' in the framework of covariant quark model

The covariant quark model represents an appropriate theoretical framework to describe the recent results on $B_{s}\rightarrow J/\psi+\eta$ and $B_{s}\rightarrow J/\psi+\eta'$ decays from the Belle collaboration. In this article we present the main features of he covariant quark model together with details on some of its aspects and methods, which we consider to be important. Further we apply the model specifically to the studied decay processes and give numerical results on decay widths as they follow from the odel. We conclude that the model, with most of its parameters previously fixed from different processes, is able to incorporate the new measurements from the Belle experiment.