Higgs boson form factor effects in $t\bar t$ production by $W^-W^+$ and $ZZ$ fusion

TL;DR

This paper investigates how Higgs boson form factors influence top-antitop production via $W^-W^+$ and $ZZ$ fusion at future electron-positron colliders, focusing on potential signs of compositeness.

Contribution

It provides an amplitude analysis identifying helicity amplitudes and cross sections most sensitive to Higgs form factors related to top quark compositeness.

Findings

Certain helicity amplitudes are highly sensitive to the $Htt$ form factor.

Specific $tar t$ polarization states enhance the detection of form factor effects.

The analysis guides experimental strategies to probe Higgs-top interactions.

Abstract

We study the fusion processes $W^-W^+\to t\bar t$ and $ZZ\to t\bar t$ observable at a future $e^-e^+$ collider and we discuss their sensitivity to an $Htt$ form factor which may be due to compositeness, in particular when the $H$ and the top quark have common constituents. We make an amplitude analysis and illustrate which helicity amplitudes and cross sections for specific final $t\bar t$ polarizations are especially sensitive to this form factor.