Multi-Higgs boson production in the Standard Model and beyond

TL;DR

Binoth et al. compute loop-induced gg→HH and gg→HHH amplitudes to assess observability at the LHC in the SM and beyond. They decompose the amplitudes into pentagon, box, and triangle topologies and examine the invalidity of the heavy-top approximation for multi-Higgs production. The study shows SM 3H rates are too small for LHC detection, while BSM scenarios with modified Yukawas, resonances, or higher-dimensional operators can yield observable cross sections (up to tens of femtobarns) in certain parameter spaces. These results position multi-Higgs production as a meaningful probe of extended Higgs sectors, with enhanced discovery prospects at future high-luminosity or higher-energy colliders.

Abstract

We present a calculation of the loop-induced processes gg -> HH and gg -> HHH, and investigate the observability of multi-Higgs boson production at the CERN Large Hadron Collider (LHC) in the Standard Model (SM) and beyond. While the SM cross sections are too small to allow observation at the LHC, we demonstrate that physics beyond the SM can lead to amplified, observable cross sections. Furthermore, the applicability of the heavy top quark approximation in two- and three-Higgs boson production is investigated. We conclude that multi-Higgs boson production at the SuperLHC is an interesting probe of Higgs sectors beyond the SM and warrants further study.

Figures (10)

• Figure 1: Illustration of different topologies to the process $gg\to hhh$.
• Figure 2: Total Higgs pair production cross section vs. $m_H$ at the LHC, as well as the individual cross sections for box (B) and triangle (T) topologies with equal ($++/--$) and opposite ($+-/-+$) helicity components.
• Figure 3: The total 3-Higgs boson production cross section vs. $m_H$ at the LHC. Equal and opposite helicity components of contributions from various topologies are shown.
• Figure 4: Renormalisation and factorisation scale dependence ($\mu=\mu_R=\mu_F$) of the 2-Higgs (left, $\mu_0=2m_H$) and 3-Higgs (right, $\mu_0=3m_H$) cross sections at the LHC.
• Figure 5: Comparison of the total cross section for 2-Higgs (left) and 3-Higgs (right) boson production vs. $m_H$ at the LHC, calculated for the physical value of $m_t$ and in the $m_t\to\infty$ limit.