Multi-Higgs Production and Unitarity in Vector-Boson Fusion at Future Hadron Colliders

TL;DR

This paper investigates multi-Higgs production via vector boson fusion at future high-energy colliders, analyzing unitarity constraints and potential measurements to explore new physics in the Higgs sector.

Contribution

It introduces an effective Lagrangian with higher-dimensional operators for VBF processes and derives unitarity constraints relevant to future collider energies.

Findings

Provides bounds on differential distributions for multi-Higgs production.

Establishes theoretical unitarity limits on new physics parameters.

Analyzes prospects for measuring multi-Higgs signals at 27 TeV and 100 TeV colliders.

Abstract

We study multi-Higgs final states in vector boson fusion (VBF) processes at the LHC and at future proton-proton colliders, focusing on the prospects for measurements at 27 TeV and at 100 TeV. We use an effective Lagrangian which includes higher-dimensional operators in the mass eigenstates which are relevant to VBF processes and relate this to specific parameterizations and models for new physics in the Higgs sector. We derive theoretical constraints on the parameter space from the unitarity of $2\to n$ scattering amplitudes and apply the results to $V V \to hh$ and $h h h$ processes, where $V=W,Z$. As a result, we present constraints on differential distributions as appropriate to the study of $V V \to hh$ and $h h h$ processes.