LHC explores what LEP hinted at: CP-violating type-I 2HDM

TL;DR

This paper investigates the potential for discovering a light charged Higgs at the LHC within a CP-violating type-I 2HDM framework, building on hints from LEP data and exploring unique decay signatures and mixing effects.

Contribution

It introduces a novel scenario where a light charged Higgs can be detected at the LHC through specific decay channels, considering CP violation and scalar-pseudo-scalar mixing effects.

Findings

Potential for significant excess in $ au u b ar{b}$ events over a wide tan beta range.

Charged Higgs loop effects can enhance Higgs decay to $ ext{γγ}$, offsetting suppressed production.

Scalar-pseudo-scalar mixing influences loop-induced Higgs signals.

Abstract

The Large Hadron Collider is shown to have great scope for a light charged Higgs discovery, in the context of the CP-violating type-I two Higgs doublet model. This scenario with similar masses of $H^\pm$ and W was suggested by the puzzling departure from charged current lepton universality found in the LEP data. With the lightest neutral Higgs mass set to 125 GeV, the charged-neutral Higgs associated production mechanism can cause a significant excess in the $\tau \nu b \bar{b}$ events over a vast range of tan beta as long as the Higgs mixing pattern avoids a few limiting cases. Thanks to the low $H^\pm$ mass, the charged Higgs loop can play a striking role in neutral Higgs decays into $\gamma \gamma$, thereby compensating for a suppressed gluon-gluon fusion rate. The effect of scalar-pseudo-scalar mixing on loop-induced Higgs signals is also discussed.