What's in the Loop? The Anatomy of Double Higgs Production

TL;DR

This paper analyzes the double Higgs production via gluon fusion to understand Higgs self-interactions and the influence of different loop particles, focusing on the invariant mass spectrum and potential new physics effects.

Contribution

It provides a detailed analytic study of the double Higgs production amplitude near threshold, highlighting how the invariant mass spectrum reveals the nature of loop particles and anomalous couplings.

Findings

High hh invariant mass spectrum is sensitive to the spin of loop particles.

Scalar and fermionic loops produce distinguishable features in the amplitude.

Anomalous top and bottom Yukawa couplings significantly affect the spectrum.

Abstract

Determination of Higgs self-interactions through the double Higgs production from gluon fusion is a major goal of current and future collider experiments. We point out this channel could help disentangle and resolve the nature of ultraviolet contributions to Higgs couplings to two gluons. Analytic properties of the double Higgs amplitudes near kinematic threshold are used to study features resulting from scalar and fermionic loop particles mediating the interaction. Focusing on the hh invariant mass spectrum, we consider the effect from anomalous top and bottom Yukawa couplings, as well as from scalar and fermionic loop particles. In particular, the spectrum at high hh invariant mass is sensitive to the spin of the particles in the loop.