@Article{ATLASCollaborationAad_etal2023, author="ATLAS Collaboration (Aad, G. et al and Amos, K. R. and Aparisi Pozo, J. A. and Bailey, A. J. and Bouchhar, N. and Cabrera Urban, S. and Cantero, J. and Cardillo, F. and Castillo Gimenez, V. and Chitishvili, M. and Costa, M. J. and Didenko and Escobar, C. and Fiorini, L. and Fullana Torregrosa, E. and Fuster, J. and Garcia, C. and Garcia Navarro, J. E. and Gomez Delegido, A. J. and Gonzalez de la Hoz, S. and Gonzalvo Rodriguez, G. R. and Guerrero Rojas, J. G. R. and Lacasta, C. and Marti-Garcia, S. and Martinez Agullo, P. and Miralles Lopez, M. and Mitsou, V. A. and Monsonis Romero, L. and Moreno Llacer, M. and Munoz Perez, D. and Navarro-Gonzalez, J. and Poveda, J. and Prades Iba{\~{n}}ez, A. and Rubio Jimenez, A. and Ruiz-Martinez, A. and Sabatini, P. and Salt, J. and Sanchez Sebastian, V. and Sayago Galvan, I. and Senthilkumar, V. and Soldevila, U. and Sanchez, J. and Torro Pastor, E. and Valero, A. and Valiente Moreno, E. and Valls Ferrer, J. A. and Varriale, L. and Villaplana Perez, M. and Vos, M.", title="Evidence of off-shell Higgs boson production from ZZ leptonic decay channels and constraints on its total width with the ATLAS detector", journal="Physics Letters B", year="2023", publisher="Elsevier", volume="846", pages="138223--29pp", abstract="This Letter reports on a search for off-shell production of the Higgs boson using 139 fb(-1) of pp collision data at root s = 13 TeV collected by the ATLAS detector at the Large Hadron Collider. The signature is a pair of Z bosons, with contributions from both the production and subsequent decay of a virtual Higgs boson and the interference of that process with other processes. The two observable final states are ZZ -> 4l and Z Z -> 2l2 nu with l = e or mu. In the ZZ -> 4l final state, a dense Neural Network is used to enhance analysis sensitivity with respect to matrix element-based discrimination. The background-only hypothesis is rejected with an observed (expected) significance of 3.3 (2.2) standard deviations, representing experimental evidence for off-shell Higgs boson production. Assuming that no new particles enter the production of the virtual Higgs boson, its total width can be deduced from the measurement of its off-shell production cross-section. The measured total width of the Higgs boson is 4.5(-2.5)(+3.3) MeV, and the observed (expected) upper limit on the total width is found to be 10.5 (10.9) MeV at 95{\%} confidence level.", optnote="WOS:001125380300001", optnote="exported from refbase (https://references.ific.uv.es/refbase/show.php?record=5926), last updated on Sun, 11 Feb 2024 18:51:44 +0000", issn="0370-2693", doi="10.1016/j.physletb.2023.138223", opturl="https://arxiv.org/abs/2304.01532", opturl="https://doi.org/10.1016/j.physletb.2023.138223", language="English" }