From B-meson anomalies to Kaon physics with scalar leptoquarks

Abstract

Abstract In this work we study possible connections between B-meson anomalies and Kaon physics observables in the context of combined solutions with the singlet and triplet scalar leptoquarks $$S_1$$ S 1 and $$S_3$$ S 3 . By assuming a flavor structure for the leptoquark couplings dictated by a minimally broken $$U(2)^5$$ U ( 2 ) 5 flavor symmetry we can make a sharp connection between these two classes of observables. We find that the bound on $${\mathcal {B}}(K^+ \rightarrow \pi ^+ \nu \nu )$$ B ( K + → π + ν ν ) from NA62 puts already some tension in the model, while the present limits on $${\mathcal {B}}(K_L \rightarrow \mu ^+ \mu ^-)$$ B ( K L → μ + μ - ) and $$\mu \rightarrow e$$ μ → e conversion in nuclei can be saturated. Relaxing instead the flavor assumption we study what values for $${\mathcal {B}}(K^+ \rightarrow \pi ^+ \nu \nu )$$ B ( K + → π + ν ν ) , as well as for $${\mathcal {B}}(K_L \rightarrow \pi ^0 \nu \nu )$$ B ( K L → π 0 ν ν ) and $${\mathcal {B}}(K_{L,S} \rightarrow \mu ^+ \mu ^-)$$ B ( K L , S → μ + μ - ) , are viable compatibly with all other phenomenological constraints.