https://doi.org/10.1140/epjc/s10052-021-09831-0
Regular Article - Theoretical Physics
The impact of top-quark modelling on the exclusion limits in 
searches at the LHC
Institute for Theoretical Particle Physics and Cosmology, RWTH Aachen University, 52056, Aachen, Germany
Received:
10
August
2021
Accepted:
15
November
2021
Published online:
25
November
2021
New Physics searches at the LHC rely very heavily on the precision and accuracy of Standard Model background predictions. Applying the spin-0 s-channel mediator model, we assess the importance of properly modelling such backgrounds in 
associated Dark Matter production. Specifically, we discuss higher-order corrections and off-shell effects for the two dominant background processes and 
in the presence of extremely exclusive cuts. Exclusion limits are calculated for state-of-the-art NLO full off-shell and predictions and compared to those computed with backgrounds in the NWA and / or at LO. We perform the same comparison for several new-physics sensitive observables and evaluate which of them are affected by the top-quark modelling. Additionally, we make suggestions as to which observables should be used to obtain the most stringent limits assuming integrated luminosities of 300 fb
and 3000 fb.
© The Author(s) 2021
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