Palatable Leptoquark Scenarios for Lepton Flavor Violation in Exclusive $b\to s{\ell }_1{\ell }_2$ modes

Abstract

We examine various scenarios that involve a light $\mathcal{O}(1TeV)$ leptoquark state and select those which are compatible with the current experimental values for $\mathcal{B}(B_s\to \mu \mu )$, $\mathcal{B}(B\to K\mu \mu {)}_{\mathrm{large}-q^2}$, $R_K={\mathcal{B}}^{\prime }(B\to K\mu \mu )/{\mathcal{B}}^{\prime }(B\to Kee)$, and which lead to predictions consistent with other experimental data. We show that two such scenarios are phenomenologically plausible, namely the one with a doublet of scalar leptoquarks of hypercharge $1/6$, and the one with a triplet of vector leptoquarks of hypercharge $2/3$. We also argue that a model with a singlet scalar leptoquark of hypercharge $1/3$ is not viable. Using the present experimental data as constraints, it is shown that the exclusive lepton flavor violating decays, $\mathcal{B}(B_s\to \mu \tau )$, $\mathcal{B}(B\to K\mu \tau )$ and $\mathcal{B}(B\to K^{\ast }\mu \tau )$, can be as large as $\mathcal{O}(10^{-5})$.

30p (published version), Interference term in Eq.(31) fixed