Explaining the $$ {B}_{d,s}\to {K}^{\left(\ast \right)}{\overline{K}}^{\left(\ast \right)} $$ non-leptonic puzzle and charged-current B-anomalies via scalar leptoquarks

Abstract

Abstract We present a model based on S1 scalar leptoquarks to solve the tension observed in the recently proposed non-leptonic optimized observables $$ {L}_{K^{\ast }{\overline{K}}^{\ast }} $$ L K ∗ K ¯ ∗ and $$ {L}_{K\overline{K}} $$ L K K ¯ . These observables are constructed as ratios of U-spin related decays based on $$ {B}_{d,s}^0\to {K}^{\left(\ast \right)0}{\overline{K}}^{\left(\ast \right)0} $$ B d , s 0 → K ∗ 0 K ¯ ∗ 0 . The model gives a one-loop contribution to the Wilson coefficient of the chromomagnetic dipole operator needed to explain the tension in both non-leptonic observables, while naturally avoiding large contributions to the corresponding electromagnetic dipoles. The necessary chiral enhancement comes from an O(1) Yukawa coupling with a TeV-scale right-handed neutrino running in the loop. We endow the model with a U(2) flavor symmetry, necessary to protect light-family flavor observables that otherwise would be in tension. Furthermore, we show that the same S1 scalar leptoquark is capable of simultaneously explaining the hints of lepton flavor universality violation observed in charged-current B-decays. The model therefore provides a potential link between two puzzles in B-physics and TeV-scale neutrino mass generation. Finally, the combined explanation of the B-physics puzzles unavoidably results in an enhancement of $$ \mathcal{B}\left(B\to K\nu \overline{\nu}\right) $$ B B → Kν ν ¯ , yielding a value close to present bounds.