Aachen 2019 – wissenschaftliches Programm
T 36.4: Vortrag
Dienstag, 26. März 2019, 16:45–17:00, S11
Search for top squark pair production in final states with one lepton using 140 fb−1 of √13 TeV data with the ATLAS experiment — David Handl, Jeannine Wagner-Kuhr, and •Paola Arrubarrena — LMU München
Natural supersymmetry models favour a relatively light supersymmetric partner of the top quark referred to as the top squark (t1), with a mass predicted up to a few TeV.
A search for top squark pair production in events with exactly one electron or muon, multiple jets and missing transverse momentum is presented. The analysis is performed using data from proton-proton collisions recorded at a center-of-mass energy of √13 TeV by the ATLAS experiment corresponding to an integrated luminosity of 140 fb−1.
This talk focuses on decay scenarios where the mass difference between the top squark and the neutralino (χ10) is smaller than the top quark (Δ m ≡ mt1 − mχ10 < mt ). In this phase-space, the top squark pair events closely resemble top quark pair processes, which make dedicated searches difficult. However, it will be shown that a substantial discrimination between signal and background processes can be achieved using machine learning techniques. In the following, the analysis strategy based on neural networks is presented, search regions and background estimation are defined and the sensitivity reach is discussed.