Study of semileptonic decay of ${\bar{B}}_s^0\to \varphi l^{+}{l}^{-}$ in QCD sum rule

Abstract

In this work we study the semi-leptonic decay of ${\bar{B}}_s^0\to \varphi l^{+}{l}^{-}$($l=e,\mu ,\tau$) with QCD sum rule method. We calculate the ${\bar{B}}_s^0\to \varphi$ translation form factors relevant to this semi-leptonic decay, then the branching ratios of ${\bar{B}}_s^0\to \varphi l^{+}{l}^{-}$($l=e,\mu ,\tau$) decays are calculated with the form factors obtained here. Our result for the branching ratio of ${\bar{B}}_s^0\to \varphi {\mu }^{+}{\mu }^{-}$ agrees very well with the recent experimental data. For the unmeasured decay modes such as ${\bar{B}}_s^0\to \varphi e^{+}{e}^{-}$ and ${\bar{B}}_s^0\to \varphi {\tau }^{+}{\tau }^{-}$, we give theoretical predictions.

25 pages, 4 figures, more content added