Charged Higgs Pairs at the LHC: A NLO Analysis

Abstract

Charged Higgs-boson pair production at hadron colliders yields information about the trilinear couplings involving charged Higgs fields in extensions of the Standard Model (SM). We consider the two-Higgs doublet model (2HDM) extension and obtain next-to-leading order QCD predictions for the charged-Higgs pair production ($H^+H^-$ production). All production modes, i.e. Drell--Yan-like production, gluon fusion and vector-boson fusion are included in the analysis. We determine uncertainties originating from the scale dependence, the parton-density functions and strong coupling $α_s$ at the LHC. We observe that the QCD corrections lead to a significant reduction of the relative scale dependences. These improved predictions will allow for a quantitative interpretation of experimental measurements, in case that charged Higgs states will be observed.

Figures (18)

• Figure 1: Typical diagrams contributing to $q\bar{q} \to V^* \to H^+H^-$ at lowest order: (a) Drell--Yan-like contribution, (b) bottom-Yukawa induced contribution.
• Figure 2: Typical diagrams contributing to $q\bar{q} \to V^* \to H^+H^-$ at NLO.
• Figure 3: The $K$ factor, defined as the ratio $\sigma_\mathrm{NLO}/\sigma_\mathrm{LO}$, for the Drell--Yan like cross section of charged-Higgs pair production as a function of the charged Higgs mass. It is the same in both 2HDM scenarios. The MSHT20lo_as130 and MSHT20nlo_as118 parton densities (PDFs) msht20 were used for the LO and NLO cross sections, respectively, for a consistent definition of the $K$ factor. The cross section is independent of $\tan\beta$ at LO and NLO.
• Figure 4: Drell--Yan like cross section of charged-Higgs pair production as a function of the charged Higgs mass with scale uncertainties. The PDF4LHC15 parton densities pdf4lhc15 have been used for the LO and NLO cross sections.
• Figure 5: Typical diagrams contributing to $gg \to H^+H^-$ at lowest order.