Scalar leptoquark contributions to the $gg\rightarrow Zh$ process

TL;DR

This paper investigates how scalar leptoquarks can influence the $gg\rightarrow Zh$ process at one-loop level, revealing new tensor structures and conditions for their contributions, with implications for new physics searches.

Contribution

It provides a systematic analysis of scalar leptoquark effects on $gg\rightarrow Zh$, highlighting the conditions under which these contributions appear and their potential observability.

Findings

Contributions only appear with off-diagonal Higgs and Z interactions.

In one-field and two-field models, contributions vanish.

In the $S_1+\widetilde{R}_2+S_3$ model, contributions depend on mass splittings and CP violation.

Abstract

In this manuscript, we study the general scalar leptoquark contributions to the $gg\rightarrow Zh$ process at one-loop level. We find that the contributions only show up for the off-diagonal Higgs and $Z$ boson interactions with scalar leptoquarks, which can lead to new tensor structures different from the standard model. In the one-field and two-field models, the contributions vanish exactly; thus, the contributions are possible at least in the three-field models. We exemplify the contributions in the $S_1+\widetilde{R}_2+S_3$ model, which can appear in the presence of scalar leptoquark mass splittings and $CP$ violation. In view of the heavy scalar leptoquark mass suppression, the leading contributions are typically small and difficult to observe at hadron colliders. However, this work offers a quantitative and systematic investigation of scalar leptoquark contributions, also making it valuable for the new physics studies in other models.