Higgs probes of top quark contact interactions and their interplay with the Higgs self-coupling

TL;DR

This paper investigates how top quark contact interactions influence Higgs production and decay, revealing that loop effects from four-quark operators can provide stronger constraints than top quark data alone and may affect Higgs self-coupling measurements.

Contribution

It calculates the impact of third generation four-quark operators on Higgs processes and explores their potential to improve constraints and interfere with Higgs self-coupling determinations.

Findings

Loop effects can yield stronger constraints than top quark data.

Four-fermion operators can affect Higgs self-coupling measurements.

Loop corrections significantly influence Higgs production and decay channels.

Abstract

We calculate the dominant contributions of third generation four-quark operators to single-Higgs production and decay. They enter via loop corrections to Higgs decays into gluons, photons and $b\bar{b}$, and in Higgs production via gluon fusion and in association with top quark pairs. We show that these loop effects can, in some cases, lead to better constraints than those from fits to top quark data. Finally, we investigate whether these four-fermion operators can spoil the determination of the trilinear Higgs self-coupling from fits to single-Higgs data.