QCD corrections to in Type-I THDM at electron positron colliders * * Supported in part by the National Natural Science Foundation of China (11775211, 11535002) and the CAS Center for Excellence in Particle Physics (CCEPP)

Abstract

We investigate in detail the charged Higgs production associated with a W boson at electron-positron colliders within the framework of the Type-I two-Higgs-doublet model (THDM). We calculate the integrated cross section at the LO and analyze the dependence of the cross section on the THDM parameters and the colliding energy in a benchmark scenario of the input parameters of the Higgs sector. The numerical results show that the integrated cross section is sensitive to the charged Higgs mass, especially in the vicinity of at a collider, and decreases consistently with the increase of in the low region. The peak in the colliding energy distribution of the cross section arises from the resonance of the loop integrals, and it moves towards the low colliding energy with the increase of . We also study the two-loop NLO QCD corrections to both the integrated cross section and the angular distribution of the charged Higgs boson and find that the QCD relative correction is also sensitive to the charged Higgs mass and strongly depends on the final-state phase space. For , the QCD relative correction at a collider varies in the range of [-10%, 11%] as increases from 150 to 400 GeV.