Deconstructing squark contributions to di-Higgs production at the LHC

TL;DR

This paper introduces a model-independent method to analyze di-Higgs production at the LHC, focusing on squark contributions within supersymmetry, revealing distinctive effects on cross sections and distributions.

Contribution

It develops a decomposition approach for di-Higgs production amplitudes, enabling detailed analysis of new physics effects, especially from top squarks in supersymmetric models.

Findings

Squark loops modify di-Higgs production cross sections.

Distinctive kinematic features arise from squark contributions.

Benchmark points suggest potential observability at the LHC.

Abstract

We present a novel approach to the study of di-Higgs production via gluon-gluon fusion at the LHC. The relevant Feynman diagrams involving two Standard Model-like Higgs bosons $hh$ are computed within a simplified model approach that enables one to interpret possible signals of new physics in a model-independent way as well as to map these onto specific theories. This is possible thanks to a decomposition of such a signal process into all its squared amplitudes and their relative interferences, each of which has a well-defined coupling structure. We illustrate the power of this procedure for the case of both a minimal and next-to-minimal representation of Supersymmetry, for which the new physics effects are due to top squarks entering the loops of $gg\to hh$. The squarks yield both a change of the integrated cross section and peculiar kinematic features in its differential distributions with respect to the Standard Model. These effects can in turn be traced back to the relevant diagrammatic and coupling structures and allow for a detailed analysis of the process. In order to do so, we perform systematic scans of the parameter spaces of such new physics scenarios and identify benchmark points which exhibit potentially observable features during the current and upcoming runs of the LHC.