Constraining Scalar Leptoquarks from the K and B Sectors

TL;DR

This paper derives bounds on scalar leptoquark couplings affecting meson mixing and decays, and explores their potential to explain CP violation anomalies in B_s mixing.

Contribution

It provides the first comprehensive constraints on all relevant scalar leptoquark couplings from K and B meson processes, including CP-violating effects.

Findings

Stringent bounds on leptoquark couplings from meson mixing data

Constraints on real and imaginary parts of couplings

Discussion of leptoquarks explaining B_s CP violation

Abstract

Upper bounds at the weak scale are obtained for all $\lambda_{ij}\lambda_{im}$ type product couplings of the scalar leptoquark model which may affect K-K(bar), B_d-B_d(bar), and B_s-B_s(bar)$ mixing, as well as leptonic and semileptonic K and B decays. Constraints are obtained for both real and imaginary parts of the couplings. We also discuss the role of leptoquarks in explaining the anomalously large CP-violating phase in B_s-B_s(bar) mixing.