Charged Higgs pairs at the LHC: A NLO analysis

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 type-I two-Higgs doublet model (2HDM) extension and obtain next-to-leading order QCD predictions for the charged-Higgs pair production ( H^+H^- <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow> <mml:msup> <mml:mi>H</mml:mi> <mml:mo>+</mml:mo> </mml:msup> <mml:msup> <mml:mi>H</mml:mi> <mml:mo>−</mml:mo> </mml:msup> </mml:mrow> </mml:math> 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 \alpha_s <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:msub> <mml:mi>α</mml:mi> <mml:mi>s</mml:mi> </mml:msub> </mml:math> 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.