Rare B and K decays in a scotogenic model

A scotogenic model can radiatively generate the observed neutrino mass, provide a dark matter candidate, and lead to rare lepton flavor-violating processes. We aim to extend the model to establish a potential connection to the quark flavor-related processes within the framework of scotogenesis, enhancing the unexpectedly large branching ratio (BR) of B^+→ K^+ νν̅, observed by Belle II Collaboration. Meanwhile, the model can address tensions between some experimental measurements and standard model (SM) predictions in flavor physics, such as the muon g-2 excess and the higher BR of B_s →μ^- μ^+. We introduce in the model the following dark particles: a neutral singlet Dirac-type lepton (N); two inert Higgs doublets (η_1,2), with one of which carrying a lepton number; a charged singlet dark scalar (χ^+), and a singlet vector-like up-type dark quark (T). The first two entities are responsible for the radiative neutrino mass, and χ^+ couples to right-handed quarks and leptons and can resolve the tensions existing in muon g-2 and B_s→μ^- μ^+. Furthermore, the BR of B^+ → K^+ νν̅ can be enhanced up to a factor of 2 compared to the SM prediction through the mediations of the dark T and the charged scalars. In addition, we also study the impacts on the K→πνν̅ decays.