%0 Journal Article
%T Anomaly detection search for new resonances decaying into a Higgs boson and a generic new particle X in hadronic final states using √s=13 TeV pp collisions with the ATLAS detector
%A ATLAS Collaboration (Aad, G. et al
%A Amos, K. R.
%A Aparisi Pozo, J. A.
%A Bailey, A. J.
%A Cabrera Urban, S.
%A Cantero, J.
%A Cardillo, F.
%A Castillo Gimenez, V.
%A Costa, M. J.
%A Didenko
%A Escobar, C.
%A Fiorini, L.
%A Fullana Torregrosa, E.
%A Fuster, J.
%A Garcia, C.
%A Garcia Navarro, J. E.
%A Gomez Delegido, A. J.
%A Gonzalez de la Hoz, S.
%A Gonzalvo Rodriguez, G. R.
%A Guerrero Rojas, J. G. R.
%A Higon-Rodriguez, E.
%A Lacasta, C.
%A Lozano Bahilo, J. J.
%A Marti-Garcia, S.
%A Martinez Agullo, P.
%A Miralles Lopez, M.
%A Mitsou, V. A.
%A Monsonis Romero, L.
%A Moreno Llacer, M.
%A Munoz Perez, D.
%A Navarro-Gonzalez, J.
%A Poveda, J.
%A Prades Ibañez, A.
%A Rubio Jimenez, A.
%A Ruiz-Martinez, A.
%A Sabatini, P.
%A Salt, J.
%A Sanchez Sebastian, V.
%A Sayago Galvan, I.
%A Senthilkumar, V.
%A Soldevila, U.
%A Sanchez, J.
%A Torro Pastor, E.
%A Valero, A.
%A Valls Ferrer, J. A.
%A Varriale, L.
%A Villaplana Perez, M.
%A Vos, M.
%J Physical Review D
%D 2023
%V 108
%N 5
%I Amer Physical Soc
%@ 2470-0010
%G English
%F ATLASCollaborationAad_etal2023
%O WOS:001088448300001
%O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=5797), last updated on Mon, 04 Dec 2023 07:57:22 +0000
%X A search is presented for a heavy resonance Y decaying into a Standard Model Higgs boson H and a new particle X in a fully hadronic final state. The full Large Hadron Collider run 2 dataset of proton-proton collisions at root s =13 TeV collected by the ATLAS detector from 2015 to 2018 is used and corresponds to an integrated luminosity of 139 fb(-1). The search targets the high Y-mass region, where the H and X have a significant Lorentz boost in the laboratory frame. A novel application of anomaly detection is used to define a general signal region, where events are selected solely because of their incompatibility with a learned background-only model. It is constructed using a jet-level tagger for signal-model-independent selection of the boosted X particle, representing the first application of fully unsupervised machine learning to an ATLAS analysis. Two additional signal regions are implemented to target a benchmark X decay into two quarks, covering topologies where the X is reconstructed as either a single large-radius jet or two small-radius jets. The analysis selects Higgs boson decays into bb, and a dedicated neural-network-based tagger provides sensitivity to the boosted heavy-flavor topology. No significant excess of data over the expected background is observed, and the results are presented as upper limits on the production cross section sigma(pp -> Y -> XH -> qqbb) for signals with m(Y) between 1.5 and 6 TeV and m(X) between 65 and 3000 GeV.
%R 10.1103/PhysRevD.108.052009
%U https://arxiv.org/abs/2306.03637
%U https://doi.org/10.1103/PhysRevD.108.052009
%P 052009-33pp