1,721,238 research outputs found
SUSY and DM searches in final states with two top quarks and missing transverse energy
No full textA search for SUSY and Dark Matter particles in association with two top quarks is presented. The supersymmetric partner of the top quark is searched for using a simplified SUSY model featuring stop pair production where each stop decays into a top quark and a neutralino, leading to a final state with two top quarks and missing transverse energy. The analysis strategy heavily uses machine learning techniques for event reconstruction and event discrimination, leading to significant improvements over previous analyses with the same dataset. In addition, simplified dark matter models are searched for where a new scalar or pseudoscalar mediator with Yukawa-like couplings is produced in association with two top quarks. This poster presents the latest ATLAS result using the full Run 2 dataset
New physics searches in tt+MET final states in pp collisions at 13 TeV with the ATLAS experiment
No full textSearch for new physics in tt̄+MET final states in pp collisions at 13 TeV with the ATLAS experiment
No full textExploring new physics with top-quark pairs: a neural network approach using atlas run-2 data
No full textA novel search for particles beyond the standard model produced in association with top-quark pairs using the ATLAS Run-2 pp dataset at √s = 13 TeV is presented. Utilising events compatible with a semileptonic decay of top-quark pairs and large missing transverse energy, the study probes direct stop quark production, spin-0 mediators decaying into dark matter particles, and effective contact interactions between top quarks and neutrinos. An innovative and inclusive analysis approach based on neural networks is introduced, enabling sensitivity to a broad spectrum of new physics models without dedicated signal region optimisation. Significant improvements in sensitivity for stop-pair production and spin-0 mediators are achieved. No significant signs of new physics have been found, exclusion limits are thus set on parameters of the simplified models probed. Stop quarks up to 1080 GeV and neutralinos up to 600 GeV are excluded at a 95% confidence level. In searches for top quarks produced in association with dark matter particles, scalar (pseudoscalar) mediators with masses up to 250 (300) GeV are excluded at a 95% confidence level. The study also interprets the data within the framework of effective vector contact interactions between top quarks and neutrinos, setting lower limits on the new physics energy scale Λ between 2.12 TeV and 2.23 TeV
Searches for New Physics with top quarks using the ATLAS detector
No full textDue to its large mass, the top quark plays a crucial role in probing the Standard Model of particle physics and beyond. The latest results from searches for new physics using top quark events collected with the ATLAS detector at the Large Hadron Collider are presented. In particular, the focus lies on scenarios beyond the Standard Model where the top quark provides is a powerful probe to answer open questions on Dark Matter and the light mass of the Higgs Boson. All searches presented utilize the full Run-2 dataset from the LHC, employing advanced techniques such as machine learning to provide the best sensitivity to new physics
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