PT Journal AU ATLAS Collaboration (Aad, Gea Amos, KR Aparisi Pozo, JA Bailey, AJ Cabrera Urban, S Cardillo, F Castillo Gimenez, V Costa, MJ Didenko Escobar, C Fiorini, L Fullana Torregrosa, E Fuster, J Garcia, C Garcia Navarro, JE Gomez Delegido, AJ Gonzalez de la Hoz, S Gonzalvo Rodriguez, GR Guerrero Rojas, JGR Higon-Rodriguez, E Lacasta, C Lozano Bahilo, JJ Mamuzic, J Marti-Garcia, S Martinez Agullo, P Miralles Lopez, M Mitsou, VA Monsonis Romero, L Moreno Llacer, M Navarro-Gonzalez, J Poveda, J Prades IbaƱez, A Ruiz-Martinez, A Sabatini, P Salt, J Sanchez Sebastian, V Sayago Galvan, I Senthilkumar, V Soldevila, U Sanchez, J Torro Pastor, E Valero, A Valls Ferrer, JA Villaplana Perez, M Vos, M TI Search for invisible Higgs-boson decays in events with vector-boson fusion signatures using 139 fb(-1) of proton-proton data recorded by the ATLAS experiment SO Journal of High Energy Physics JI J. High Energy Phys. PY 2022 BP 104 EP 66pp VL 08 IS 8 DI 10.1007/JHEP08(2022)104 LA English DE Hadron-Hadron Scattering; Higgs Physics; Vector Boson Production AB A direct search for Higgs bosons produced via vector-boson fusion and subsequently decaying into invisible particles is reported. The analysis uses 139 fb(-1) of pp collision data at a centre-of-mass energy of root s =13 TeV recorded by the ATLAS detector at the LHC. The observed numbers of events are found to be in agreement with the background expectation from Standard Model processes. For a scalar Higgs boson with a mass of 125 GeV and a Standard Model production cross section, an observed upper limit of 0.145 is placed on the branching fraction of its decay into invisible particles at 95% confidence level, with an expected limit of 0.103. These results are interpreted in the context of models where the Higgs boson acts as a portal to dark matter, and limits are set on the scattering cross section of weakly interacting massive particles and nucleons. Invisible decays of additional scalar bosons with masses from 50 GeV to 2 TeV are also studied, and the derived upper limits on the cross section times branching fraction decrease with increasing mass from 1.0 pb for a scalar boson mass of 50 GeV to 0.1 pb at a mass of 2 TeV. ER