# NLO predictions for Higgs boson pair production with full top quark mass dependence matched to parton showers

## TL;DR

This paper presents the first NLO QCD predictions for Higgs boson pair production that include full top quark mass dependence, matched with parton showers, providing more accurate theoretical tools for experimental analysis.

## Contribution

It combines NLO matrix elements with parton showers for di-Higgs production including full top mass dependence, implemented in POWHEG-BOX and MadGraph5_aMC@NLO frameworks.

## Key findings

- Shower effects are significant for certain observables like Higgs pair transverse momentum.
- Differences between full NLO and HEFT approximation are larger than shower effects in distribution tails.
- The results reduce theoretical uncertainties in Higgs pair production predictions.

## Abstract

We present the first combination of NLO QCD matrix elements for di-Higgs production, retaining the full top quark mass dependence, with a parton shower. Results are provided within both the POWHEG-BOX and MadGraph5_aMC@NLO Monte Carlo frameworks. We assess in detail the theoretical uncertainties and provide differential results. We find that, as expected, the shower effects are relatively large for observables like the transverse momentum of the Higgs boson pair, which are sensitive to extra radiation. However, these shower effects are still much smaller than the differences between the Born-improved HEFT approximation and the full NLO calculation in the tails of the distributions.