Searching for charged Higgs bosons with flavor-changing couplings at the LHC

TL;DR

The paper investigates charged Higgs bosons in the G2HDM with flavor-changing couplings $\rho_{tc}$ as a path to test FCNH physics and possible links to electroweak baryogenesis. It proposes a collider-focused strategy: resonant $c\bar{b} \to H^+$ production followed by $H^+ \to W^+ H$ and the subsequent $H \to t\bar{c}$ decay, yielding a same-sign dilepton signature. A detector-level MC study at $\sqrt{s}=14~\mathrm{TeV}$ with two benchmark points demonstrates discovery prospects at $L=300~\mathrm{fb}^{-1}$ with significances of about $7.4\sigma$ and $8.8\sigma$ under a 10% systematic on the background. The work also discusses current constraints on $\rho_{tc}$ from $t \to ch$ searches and FCNH heavy-Higgs analyses, highlighting the potential to measure $\rho_{tc}$ and illuminate the connection to the Universe's baryon asymmetry.

Abstract

We investigate the LHC discovery prospects for charged Higgs bosons in the general two Higgs doublet model (G2HDM) that has flavor-changing neutral Higgs (FCNH) couplings. The FCNH $ρ_{tc}$ coupling induces intriguing $H^+$ production processes $c\bar b \to H^+$, $cg \to bH^+$, and $\bar bg \to \bar cH^+$ without CKM suppression. Sizable $ρ_{tc}$ can drive the disappearance of antimatter from the Universe. In this contribution, we promote the resonant $c\bar b \to H^+$ production, followed by the bosonic $H^+ \to W^+ H$ decay. Discovery could be a harbinger of G2HDM with FCNH couplings, and perhaps shed light on the baryon asymmetry of the Universe.

Figures (2)

• Figure 1: Exclusion bound from $t \to ch$ search in the $|c_\gamma|$-$|\rho_{tc}|$ plane.
• Figure 2: The normalized $H_T$ distribution for the signal and background processes.