Aad, G.Abbott, B.Abeling, K.Abicht, N.J.Abidi, S.H.Aboulhorma, A.Abramowicz, H.Abreu, H.Abulaiti, Y.Acharya, B.S.Adam Bourdarios, C.Adamczyk, L.Addepalli, S.V.Addison, M.J.Adelman, J.Adiguzel, A.Adye, T.Affolder, A.A.Afik, Y.Agaras, M.N.et al.2025-04-142025-04-142024Physical Review Letters, 2024; 133(14):141801-1-141801-220031-90071079-7114https://hdl.handle.net/2440/144194Published 2 October 2024The associated production of Higgs and 𝑊 bosons via vector-boson fusion is highly sensitive to the relative sign of the Higgs boson couplings to 𝑊 and 𝑍 bosons. In this Letter, two searches for this process are presented, using 140  fb⁻¹ of proton-proton collision data at √𝑠=13  TeV recorded by the ATLAS detector at the LHC. The first search targets scenarios with opposite-sign couplings of the 𝑊 and 𝑍 bosons to the Higgs boson, while the second targets standard model-like scenarios with same-sign couplings. Both analyses consider Higgs boson decays into a pair of 𝑏 quarks and 𝑊 boson decays with an electron or muon. The data exclude the opposite-sign coupling hypothesis with a significance beyond 5⁢𝜎, and the observed (expected) upper limit set on the cross section for vector-boson fusion 𝑊⁢𝐻 production is 9.0 (8.7) times the standard model value at 95% confidence level.en© 2024 CERN, for the ATLAS Collaboration. Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.ATLAS CollaborationJournal article10.1103/physrevlett.133.141801712579Filmer, E.K. [0000-0001-6967-7325]Jackson, P. [0000-0002-0847-402X]Kong, A.X.Y. [0000-0001-8063-8765]McDougall, A.E. [0000-0001-7713-2800]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]