Leptoquark effects on and decay processes

Abstract

We study the rare semileptonic decays of B mesons induced by $b\to s\nu \bar{\nu }$ as well as $b\to {{sl}}^{+}{l}^{-}$ transitions in the scalar leptoquark (LQ) model, where the LQs have the representation (3, 2, 7/6) and (3, 2, 1/6) under the standard model gauge group. The LQ parameter space is constrained using the most recent experimental results on ${\rm{Br}}({B}_{s}\to {\mu }^{+}{\mu }^{-})$ and ${\rm{Br}}({B}_{d}\to {X}_{s}{\mu }^{+}{\mu }^{-})$ processes. Considering only the baryon number conserving LQ interactions, we estimate the branching ratios for the exclusive $\bar{B}\to {\bar{K}}^{(\ast )}\nu \bar{\nu }$ and inclusive $B\to {X}_{s}\nu \bar{\nu }$ decay processes by using the constraint parameters. We also obtain the low recoil (large lepton invariant mass, i.e., ${q}^{2}\sim {m}_{b}^{2}$ ) predictions for the angular distribution of $\bar{B}\to \bar{K}{l}^{+}{l}^{-}$ process and several other observables including the flat term and lepton flavour non-universality factor in this model.

Keywords

• B physics
• rare decays
• leptoquark model
• 13.20.He
• 12.60.-i
• 14.80.Sv