Karlsruhe 2024 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

T: Fachverband Teilchenphysik

T 23: Top physics 1

T 23.4: Vortrag

Montag, 4. März 2024, 16:45–17:00, Geb. 30.95: Audimax

Search for same-sign top pair production with the Standard Model Effective Field Theory at the ATLAS experiment — Noemi Cavalli^1,2, Merve Nazlim Agaras³, Maximiliano Sioli², Matteo Negrini², Kevin Alexander Kroeninger¹, Aurelio Juste Rozas Rozas³, and •Aaron van der Graaf^1,2 — ¹Technical University of Dortmund — ²University of Bologna — ³The Institute for High Energy Physics of Barcelona

Model-independent searches for new physics at high energies by using the Standard Model (SM) Effective Field Theory (SMEFT) are an important part of todays physics program. Same-sign top-quark pair production is highly suppressed in the SM while several models beyond the SM enhance the production. SMEFT is used obtain model-independent predictions for the production of the same-sign top pairs beyond the SM. Three EFT operators are considered to simulate the searched signal. The full Run 2 dataset collected by the ATLAS detector from proton-proton collisions is used for this search for same-sign top-quark pairs, in the dilepton final state. A Neural Network (NN) is employed to build separate signal regions (SR) enriched in same-sign top events resulting from different EFT operators. Within the defined SRs, a second NN is applied to perform a signal-background discrimination. In order to attain an accurate estimation of background contributions in the SRs, several Control Regions (CRs) are defined. The background estimation and the signal search are performed by using a maximum likelihood fit over all analysis regions.

Keywords: EFT; Top-Quark; BSM; Data-analysis; NN