Heidelberg 2022 – wissenschaftliches Programm

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T: Fachverband Teilchenphysik

T 33: Top Quarks: Production (Exp.) 2

T 33.6: Vortrag

Dienstag, 22. März 2022, 17:30–17:45, T-H18

Background model in a ttW cross-section measurement — •Marcel Niemeyer, Arnulf Quadt, and Elizaveta Shabalina — Georg-August University Goettingen

The top-quark pair production in association with a W boson is an interesting process by itself and exhibit an important background to processes like ttH or 4-tops production. Due to higher order electroweak corrections, the process is difficult to model. In consequence, a mismodelling of ttW has been observed in previous analyses. Thus, it is of high importance to measure this process to improve our understanding of it. The analysis is performed in the multi-lepton channel requiring 2ℓ (same-sign) or 3ℓ. The resulting event sample has a significant contribution from fake backgrounds.

To estimate this background, an extended template fit is performed that uses a discriminant based on isolation and b-tagging variables, referred to as a prompt lepton veto. The fit, the calibration of the prompt lepton veto, and the related systematic uncertainties will be discussed in this talk.