Resolving the $(g-2)_{\mu}$ and $B$ anomalies with leptoquarks and a dark Higgs boson

TL;DR

This paper proposes a model with leptoquarks and a dark Higgs boson to simultaneously explain the muon g-2 and B-meson anomalies, predicting new decay modes within experimental reach.

Contribution

It introduces a combined two-Higgs-doublet, leptoquark, and dark Higgs model that addresses multiple anomalies and predicts novel decay processes.

Findings

A consistent parameter space resolves both anomalies.

Predicted decay modes are near current experimental bounds.

TeV-scale leptoquarks and MeV-scale dark Higgs are key components.

Abstract

At present, there are outstanding discrepancies between standard model predictions and measurements of the muon's $g-2$ and several $B$-meson properties. We resolve these anomalies by considering a two-Higgs-doublet model extended to include leptoquarks and a dark Higgs boson $S$. The leptoquarks modify $B$-meson decays and also induce an $S \gamma \gamma$ coupling, which contributes to the muon's $g-2$ through a Barr-Zee diagram. We show that, for TeV-scale leptoquarks and dark Higgs boson masses $m_{S} \sim 10-200~\text{MeV}$, a consistent resolution to all of the anomalies exists. The model predicts interesting new decays, such as $B \to K^{(*)} e^+ e^-$, $B \to K^{(*)} \gamma \gamma$, $K \to \pi \gamma \gamma$, and $h \to \gamma \gamma \gamma \gamma$, with branching fractions not far below current bounds.