2941311 20250829210235.0 oai:cds.cern.ch:2941311 cerncds:FULLTEXT ATL-PHYS-SLIDE-2025-412 eng ATL-COM-PHYS-2025-625 The ATLAS collaboration Search for new physics in final states with semi-visible jets or anomalous signatures using the ATLAS detector 2025 CERN Geneva 29 Aug 2025 14 p Park, Ki Ryeong AUTHOR|(CDS)2752566 Columbia University (US) k.park@cern.ch A search is presented for hadronic signatures of beyond the Standard Model (BSM) physics, with an emphasis on signatures of a strongly-coupled hidden dark sector accessed via resonant production of a Z' mediator using 140fb-1 of Run-2 pp collision data at 13 TeV. The Z' mediator is considered to decay to two dark quarks, each of which then hadronizes and decays to showers containing both dark and Standard Model particles, producing a topology of interacting and non-interacting particles within a jet known as "semi-visible". Machine learning methods are used to select events with semi-visible jets and reject the dominant background of mismeasured multijet events, including an anomaly detection approach to preserve broad sensitivity to a variety of BSM topologies. SLIDE CERN CDS-Invenio WebSubmit Particle Physics - Experiment SzGeCERN Physics SzGeCERN CERN Experimental results CERN Dark matter CERN Dark sector CERN Z' mediator CERN Anomaly Detection CERN Variational Autoencoder CERN Particle Flow Network CERN EXOTICS CERN INTNOTE PRIVATLAS PUBLATLASSLIDE CERN LHC ATLAS PH-EP ATLAS Collaboration http://cds.cern.ch/record/2939593 Original Communication (restricted to ATLAS) 2776391 2667785 http://cds.cern.ch/record/2941311/files/ATL-PHYS-SLIDE-2025-412.pdf k.park@cern.ch n 202570 91 2939468 madison20250825 PUBLIC 000787670CER PUBLATLASSLIDE Slides