LAUSR

We investigate in detail both transverse momentum and threshold resummation effects on the scalar-pseudoscalar pair production via quark-antiquark annihilation at the \begin{document}$ 13 \; \text{TeV}$\end{document} Large Hadron Collider at the QCD NLO+NLL accuracy. A factorization method is introduced to supplement properly the soft-gluon (threshold) resummation contribution from parton distribution functions to the resummed results obtained by the Collins-Soper-Sterman resummation approach. We find that the impact of the threshold-resummation improved PDFs is comparable to the resummation effect from the partonic matrix element and can even predominate in high invariant mass region. Moreover, the loop-induced gluon-gluon fusion channel in the type-I two-Higgs-doublet model is also taken into account in our calculation. Our numerical results show that the electroweak production via quark-antiquark annihilation dominates over the gluon-initiated QCD production by \begin{document}$ 1 \sim 2$\end{document} orders of magnitude.