Impact of vector leptoquark on $\bar{B}\to {\bar{K}}^{\ast }{l}^{+}{l}^{-}$ anomalies

Abstract

Motivated by the recent measurement of the lepton flavour nonuniversality ratio $R_{K^{\ast }}$ by the LHCb Collaboration, we study the implications of vector leptoquarks on the observed anomalies associated with the $\bar{B}\to {\bar{K}}^{\ast }{l}^{+}{l}^{-}$ decay processes. The leptoquark couplings are constrained from the measured branching ratios of $B_s\to l^{+}{l}^{-}$, $K_L\to l^{+}{l}^{-}$ and $B_s\to {\mu }^{\mp }{e}^{\pm }$ processes. Using these constrained couplings, we estimate the branching ratios, forward-backward and lepton polarization asymmetries and also the form factor independent optimized observables ($P_i^{(\prime )}$) for $\bar{B}\to {\bar{K}}^{\ast }{l}^{+}{l}^{-}$ modes in the high recoil limit. We also study the other lepton flavour universality violating observables, such as $Q_{F_{L,T}}$, $Q_i$ and $B_{5,6s}$, where $i=1,2,\cdots 6,8$. Furthermore, we investigate the lepton flavour violating $K_L\to {\mu }^{\mp }{e}^{\pm }$ decay process in this model.

Comments: 26 pages, 10 figures, to appear in Jour. Phys. G