COMETA workshop on EFT in HH and VBS

Session

ATLAS internal discussion

19 Mar 2025, 10:00

Paris

Presentation materials

ATLAS private discussion agenda

20. First look at dim-8 EFT operators in VBF hh->HH

Thiziri Amezza (Centre National de la Recherche Scientifique (FR))

This study aims to probe the boosted Higgs boson pair production (HH) via Vector Boson Fusion process (VBF) which has unique sensitivity for the so far unmeasured quartic Higgs-gauge coupling (HHVV) at leading order. To explore this, we are investigating the dimension-8 Effective Field Theory (EFT) operators within the VBF HH framework, using the extended aqgc model. This model builds upon the...

30. Sensitivity study of VBS process to dimention-8 EFT operators

Sijing Zhang (L2IT/Université de Toulouse, CNRS/IN2P3 (FR))

The new dimention-8 EFT model for the quartic couplings in HEFT has been enclosed recently. This model contains the 5 effective operators that appear at order p^4 (NLO in HEFT), which has been demonstrated to have contribution to the VBS processes. The first sensitivity study of this model for the VBS processes at ATLAS will be shown in this talk.

16. The effect of single Higgs backgrounds and Higgs branching fractions in the SMEFT interpretation

Dr Ligang Xia (Nanjing University (CN))

Some SMEFT parameters contribute to both di-Higgs and single-Higgs productions. Taking the HH->bbyy channel (JHEP 01(2024) 066) as example, we present the results on the effects of single Higgs backgrounds and Higgs branching fractions and discuss about the evaluation of systematical uncertainties.

19. VBS aQGC Reweighting study

Olivier Salin (Université Paris-Saclay)

This talk will present an investigation into generating EFT aQGC samples using the internal Madgraph LO matrix element reweighting method. The study focuses on the semi-leptonic VBS process applied to the new aQGC recommendation superset of the Eboli model. The aim is to assess the accuracy and reliability of the approach and, if possible, validate it as an alternative to the EFT decomposition...