Collider probe of heavy additional Higgs bosons solving the muon $g-2$ and dark matter problems

TL;DR

This paper explores the potential of the LHC to detect heavy Higgs bosons in a model addressing both the muon g-2 anomaly and dark matter, focusing on single scalar production to extend the search reach.

Contribution

It introduces a novel LHC search strategy for single production of flavor-violating Higgs scalars, enhancing detection prospects up to 1 TeV mass range.

Findings

Single scalar production extends LHC reach to 1 TeV.

Flavor-violating signatures provide distinctive signals.

Model simultaneously explains muon g-2 and dark matter.

Abstract

We study the Large Hadron Collider (LHC) search potential of a $\mathbb{Z}_4$-based two Higgs doublet model which can simultaneously explain the muon $g-2$ anomaly and the observed dark matter. The neutral scalars in the second Higgs doublet couple to $\mu$ and $\tau$ and largely contribute to the muon anomalous magnetic moment through the one-loop diagram involving $\tau$ and scalars. An additional singlet scalar which is charged under the discrete symmetry can be a dark matter candidate. An upper limit on the scalar mass originates from the unitarity constraint, and the $\mu\tau$ flavor-violating nature of the scalars predicts non-standard signatures at the LHC. However, the previously proposed $\mu^\pm\mu^\pm\tau^\mp\tau^\mp$ signal via the electroweak heavy neutral scalar pair production at the LHC loses sensitivity for increasing scalar mass. We revisit this model and investigate the LHC prospects for the single production of the $\mu\tau$ flavor-violating neutral scalar. It is shown that the single scalar process helps to extend the LHC reach to the 1$\,$TeV mass regime of the scenario. The search potential at the high energy LHC is also discussed.