Hayrapetyan, A.Tumasyan, A.Adam, W.Andrejkovic, J.W.Bergauer, T.Chatterjee, S.Damanakis, K.2026-04-252026-04-2520251029-8479https://doi.org/10.1007/JHEP10(2025)219https://hdl.handle.net/11486/8003A first study is presented of the cross section for the scattering of same-sign W boson pairs via the detection of a τ lepton. The data from proton-proton collisions at the center-of-mass energy of 13 TeV were collected by the CMS detector at the LHC, and correspond to an integrated luminosity of 138 fb−1. Events were selected that contain two jets with large pseudorapidity and large invariant mass, one τ lepton, one light lepton (e or μ), and significant missing transverse momentum. The measured cross section for electroweak same-sign WW scattering is times the standard model prediction. In addition, a search is presented for the indirect effects of processes beyond the standard model via the effective field theory framework, in terms of dimension-6 and dimension-8 operators. © The Author(s) 2025.eninfo:eu-repo/semantics/openAccessHadron-Hadron ScatteringVector Boson ProductionArticle20251010.1007/JHEP10(2025)2192-s2.0-105025377780Q1