Aad, G.Aakvaag, E.Abbott, B.Abdelhameed, S.Abeling, K.Abicht, N.J.Abidi, S.H.Aboelela, M.Aboulhorma, A.Abramowicz, H.Abreu, H.Abulaiti, Y.Acharya, B.S.Ackermann, A.Adam Bourdarios, C.Adamczyk, L.Addepalli, S.V.Addison, M.J.Adelman, J.Adiguzel, A.et al.2025-09-092025-09-092025Physics Letters B, 2025; 861:139277-1-139277-210370-26931873-2445https://hdl.handle.net/2440/147211LetterThis Letter presents a constraint on the total width of the Higgs boson (Γ(𝐻)) using a combined measurement of on-shell Higgs boson production and the production of four top quarks, which involves contributions from offshell 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% cofidence level upper limit on Γ(𝐻) 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).en© 2025 CERN for the benefit of the ATLAS Collaboration. Published by Elsevier B.V. Funded by SCOAP³. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Higgs bosonJournal article10.1016/j.physletb.2025.139277727128Gallagher, J. [0000-0001-9284-6270]Jackson, P. [0000-0002-0847-402X]Kong, A.X.Y. [0000-0001-8063-8765]Oliver, J.L. [0000-0002-0713-6627]Pandya, H.D. [0000-0002-1199-945X]Potti, H. [0000-0002-0800-9902]Ruggeri, T.A. [0000-0001-9941-1966]Ting, E.X.L. [0000-0002-5886-6339]White, M.J. [0000-0001-5474-4580]