CP-odd Higgs boson production in association with Neutral gauge boson in High-Energy $e^+e^-$ Collisions

TL;DR

This paper investigates the production of a CP-odd Higgs boson with neutral gauge bosons in high-energy electron-positron collisions within Two Higgs Doublet Models, highlighting the impact of $ aneta$ on production rates.

Contribution

It provides a detailed one-loop level analysis of $A^0$ production in $e^+e^-$ collisions, emphasizing the role of top quark loops at small $ aneta$ regimes.

Findings

Significant cross-sections (~a few fb) at small $ aneta$ due to top quark loops.

Cross-sections are negligible at large $ aneta$, making detection challenging.

Analysis enhances understanding of Higgs production mechanisms in extended models.

Abstract

We study the associated production of a CP-odd Higgs boson $A^0$ with a neutral gauge boson ($Z$ or photon) in high-energy $e^+ e^-$ collisions at the one-loop level in the framework of Two Higgs Doublet Models (THDM). We find that in the small $\tan\beta$ regime the top quark loop contribution is enhanced leading to significant cross-sections (about a few fb), while in the large $\tan\beta$ regime the cross-section does not attain observable rates.