One of the LHC's priorities, following the discovery of the Higgs boson, is to observe the production of Higgs pairs and to measure the Higgs tri-linear coupling $\lambda_{3H}$.
Due to the rarity of di-Higgs production, measuring $\lambda_{3H}$ has proven to be highly challenging. Exclusion limits have been observed using a variety of approaches, including cut-based methods and boosted...
We have studied the production of 2, 3 and 4 Higgs bosons from the collision of Goldstone bosons using the equivalence theorem in HEFT. This work has been compared with results from both ATLAS and CMS. The measurements are being updated by the collaborations with the latest results.
Vector Boson Scattering in the WZ fully leptonic channel was studied in ATLAS with the full Run 2 data of 140 fb-1 and the results were published recently. The importance of the channel for the study of the Electroweak Symmetry Breaking and for indirect New Physics searches beyond the Standard Model will be presented. The results of the cross section measurements will be discussed and the...
We present a calculation of the NLO QCD corrections to Higgs boson pair production in vector boson fusion, combined with the leading operators parametrising anomalous interactions in non-linear Effective Field Theory (HEFT). Based on our Monte Carlo implementation using GoSam+Whizard, we investigate the effects of anomalous Higgs couplings on various observables.
We have explored the effects of different HEFT coefficients to the multiple Higgs production via VBF at various colliders, studying their potential accessibility. We have also matched the bosonic HEFT to the 2HDM and the SMEFT in VBF processes.
The process of double Higgs boson production via vector boson fusion (VBF), although strongly suppressed compared to the gluon fusion channel, remains an important area of study. Not only can it provide valuable insights into the EW sector and the mechanism of EWSB, but it is also highly sensitive to BSM physics. In this talk, we explore the impact of dimension-6 and dimension-8 SMEFT...
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...
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.
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.
Vector boson scattering (VBS) processes probe the fundamental structure of electroweak (EW) interactions and provide a high sensitivity to new physics phenomena affecting gauge and Higgs couplings. The semileptonic final states, where one of the scattered electroweak boson decays hadronically into a quark/antiquark pair and the other boson decays leptonically into electrons, muons or...
