Correlative study of flavor anomalies and dark matter in the light of scalar leptoquark

TL;DR

This paper investigates a $U(1)_{L_e-L_mu}$ gauge extension of the Standard Model, linking flavor anomalies and dark matter through scalar leptoquarks, neutrino mass mechanisms, and new gauge interactions, constrained by flavor and dark sector data.

Contribution

It introduces a novel model combining scalar leptoquarks, neutrino mass generation, and dark matter within a gauge extension, analyzing its implications for flavor anomalies and dark matter detection.

Findings

Model explains $b o s$ anomalies via $Z'$ penguin diagrams.

Parameter space consistent with flavor observables and dark matter constraints.

Predictions for decay observables and lepton non-universality effects.

Abstract

We explore $U(1)_{L_e-L_\mu}$ gauge extension of the Standard Model with particle content enlarged by three neutral fermions, of which the lightest one contributes to dark matter content of the Universe. The scalar sector is enriched with a $\tilde{R}_2$ scalar leptoquark doublet to investigate flavor anomalies in $B$-meson sector, an additional inert scalar doublet to realize neutrino mass at one loop and a scalar singlet to spontaneously break the new $U(1)$. We discuss dark matter relic density and direct detection cross section in scalar and gauge portals. New physics contribution for $b \to s$ transition comes from penguin diagrams with $Z^\prime$, leptquark and new fermions. We analyze the constraints on the model parameters from the established observables of $B \to K^{(*)} \mu^+ \mu^-$ and $B_s\to \phi \mu^+ \mu^-$ decay channels. Utilizing the permissible parameter space consistent with both flavor and dark sectors, we discuss the impact on various observables such as branching ratio, forward-backward asymmetry, longitudinal polarisation asymmetry, and also lepton non-universality of $\Lambda_b \to \Lambda ^* (1520) (\to pK) \ell ^+\ell ^-$ decay channel.