Aad, G.Aakvaag, E.Abbott, B.Beddall, Andrew JohnÇelebi,Öztürk, SertaçŞahinsoy, MerveŞimşek, SinemUysal, Zekeriya2025-04-182025-04-182025Aad, G., Aakvaag, E., Abbott, B., Abdelhameed, S., Abeling, K., Abicht, N. J., ... & Bahner, D. (2025). Constraint on the total width of the Higgs boson from Higgs boson and four-top-quark measurements in pp collisions at s= 13 TeV with the ATLAS detector. Physics Letters B, 139277.03702693http://dx.doi.org/10.1016/j.physletb.2025.139277https://hdl.handle.net/20.500.12713/7088This Letter presents a constraint on the total width of the Higgs boson (ΓH) using a combined measurement of on-shell Higgs boson production and the production of four top quarks, which involves contributions from off-shell Higgs boson-mediated processes. This method relies on the assumption that the tree-level Higgs-top Yukawa coupling strength is the same for on-shell and off-shell Higgs boson production processes, thereby avoiding any assumptions about the relationship between on-shell and off-shell gluon fusion Higgs production rates, which were central to previous measurements. The result is based on up to 140 fb−1 of proton–proton collisions at a centre-of-mass energy of s = 13 TeV collected with the ATLAS detector at the Large Hadron Collider. The observed (expected) 95% confidence level upper limit on ΓH is 450 MeV (75 MeV). Additionally, considering the constraint on the Higgs-top Yukawa coupling from loop-induced Higgs boson production and decay processes further yields an observed (expected) upper limit of 160 MeV (55 MeV). © 2025 CERN for the benefit of the ATLAS Collaborationeninfo:eu-repo/semantics/openAccessOther8612-s2.0-8521592515910.1016/j.physletb.2025.139277Q1