Interference effects and the use of Higgs boson pair production to study the Higgs trilinear self coupling

TL;DR

This paper investigates the interference effects in Higgs boson pair production via gluon fusion, revealing an energy-independent destructive interference pattern that impacts the measurement of the Higgs self-coupling across a wide range of collider energies.

Contribution

It demonstrates that the interference structure in Higgs pair production is largely energy-independent and nearly maximally destructive, providing new insights for Higgs self-coupling studies.

Findings

Interference effects are energy-independent between 8 TeV and 100 TeV.

The interference is almost maximally destructive across various production mechanisms.

The magnitude of interference varies significantly among different mechanisms.

Abstract

We show that the dominant channel proposed for the determination of the Higgs boson trilinear coupling, $pp\to HH+X$ via gluon fusion, exhibits an interference structure that is independent of the collider energy for collider energies in the range $8\,{\rm TeV}\leq \sqrt{s}\leq 100\,{\rm TeV}$ and is almost maximally destructive. This insensitivity to the collider energy remains approximately true for a variety of other two Higgs production mechanisms although the magnitude of the interference varies widely.