Year: 2026
Type: article
Abstract: A bstract The non-resonant production of a Higgs boson pair in association with a top-antitop quark pair $$ \left( pp\to t\overline{t} hh\right) $$ pp → t t ¯ hh has only recently begun to be explored at the Large Hadron Collider (LHC) and provides a unique and largely uncharted probe of the top-Higgs sector, offering complementary sensitivity to the Higgs self-coupling and higher-dimensional interactions beyond the Standard Model. In this work, we present a detailed study of this process within the framework of Higgs Effective Field Theory (HEFT) at the High-Luminosity LHC (HL-LHC). A comparative analysis is performed using a traditional cut-based approach in the single-lepton channel and a multivariate parametric boosted decision tree method in both single-lepton and dilepton final states. We derive one- and two-parameter limits at 95% confidence level on the HEFT couplings δκ λ , c 2 , c 2 g , c tg , and c tg 2 . The projected bound on δκ λ is weaker than current experimental constraints from dedicated Higgs-pair measurement; however, this coupling plays a critical role in shaping the multidimensional allowed parameter space. For the remaining HEFT couplings, where no direct experimental limits currently exist, our results provide the first sensitivity projections in the $$ t\overline{t} hh $$ t t ¯ hh channel. Overall, this study demonstrates the strong potential of the $$ t\overline{t} hh $$ t t ¯ hh production process to probe extended Higgs and top-quark interactions beyond the Standard Model through the exploitation of the $$ t\overline{t} hh $$ t t ¯ hh data at the HL-LHC.
Source: Journal of High Energy Physics
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W7169539592