Semileptonic decays $B/B_s\to (\eta ,\text{etar},G)(l^{+}{l}^{-},l\bar{\nu },\nu \bar{\nu })$ in the perturbative QCD approach beyond the leading order

Abstract

In this paper we make a systematic study of the semileptonic decays $B/B_s\to (\eta ,\text{etar},G)(l^{+}{l}^{-},l\bar{\nu },\nu \bar{\nu })$ by employing the perturbative QCD (pQCD) factorization approach. The next-to-leading-order (NLO) contributions to the relevant form factors are included, and the ordinary $\eta$-$\text{etar}$ mixing scheme and the $\eta$-$\text{etar}$-$G$ mixing scheme are considered separately, where $G$ denotes a pseudoscalar glueball. The numerical results and the phenomenological analysis indicate that (a) the NLO contributions to the relevant form factors provide 25% enhancement to the leading-order pQCD predictions for the branching ratios $Br(B^{-}\to {\eta }^{{(}^{\prime })}{l}^{-}{\bar{\nu }}_l)$, leading to a good agreement between the predictions and the data; (b) for all considered decays, the pQCD results are basically consistent with those from other different theoretical models; (c) the pQCD predictions in the two considered mixing schemes agree well with each other within theoretical errors. The outcomes presented here can be tested by LHCb and forthcoming Super-$B$ experiments.

Comments: 8 pages, 1 figure. Published in Phys.Rev. D87, 097501 (2013)