Scotogenic Dirac neutrino mass models embedded with leptoquarks: one pathway to address the flavor anomalies and the neutrino masses together

Abstract

If the leptoquarks proposed to account for the intriguing anomalies observed in the B-meson decays, R D ( * ) and R K ( * ) , as well as in the anomalous magnetic moment of the muon, (g − 2)µ, can be embedded into the scotogenic Dirac neutrino model, all these flavor anomalies, together with the origin of neutrino masses and the nature of dark matter, would be potentially addressed in a unified picture. Among the minimal seesaw, one-loop, and two-loop realizations of the dimension-4 effective operator L4 for the Dirac neutrino masses, we show that plenty of diagrams associated with the two-loop realizations of L4 can support the coexistence of leptoquarks and dark matter candidates. After a simple match of these leptoquarks to those that can accommodate all the flavor anomalies, we establish the scotogenic Dirac neutrino models embedded with leptoquarks, which could address all the problems mentioned above.

The flavor of a minimal composite S1 leptoquark and the $$ b\to c\tau \overline{\nu} $$ anomaly

“…P r is a projector from the representation of SO (11) of ψ, to the representation r of SO (10), such that a product as ( ψf Σ)P r (Σ † ψ f ′ ) (c) is superficially an invariant of SO (10), and thanks to the properties of Σ it is also an invariant of SO (11). There is one form factor Π f f ′(c) for each invariant, we give some examples of the form factors contained in L eff : for terms ∼ ψq × ψ q , since 55 ∼ 45 ⊕ 10, one has Π 45 qq and Π 10 qq ; for terms ∼ ψq × ψ u , since 165 ∼ 120 ⊕ 45, there is only one common SO (10) representation contained in these fermions and one has Π 45 qu ; for ∼ ψq × ψ c l , since 11 ∼ 10 ⊕ 1, the common SO (10) representation contained in these fermions is 10 and one has Π 10 ql c . By making use of the decompositions of appendix A it is straightforward to obtain the values that r can take for the different correlators.…”