Rare semileptonic B-S decays to eta and eta ' mesons in QCD

Abstract

We analyze the rare semileptonic B-S -> (eta, eta')l(+)l(-), (l = e, mu, tau), and B-S -> (eta, eta')v (v) over bar transitions probing the (s) over bars content of the eta and eta' mesons via three-point QCD sum rules. We calculate responsible form factors for these transitions in full theory. Using the obtained form factors, we also estimate the related branching fractions and longitudinal lepton polarization asymmetries. Our results are in a good consistency with the predictions of the other existing nonperturbative approaches.