Analysis presents Monte Carlo generator comparisons of the ttW processes at particle level. The aim is to compare the modelling of some important backgrounds to ttH measurements in the Higgs to multi-lepton decay channels and the treatment of the associated theory uncertainties for a full Run-2 ATLAS+CMS combination. As a first step, pre-fit modelling and theory uncertainties as used in the experiments are compared in the relevant analysis regions.
This analysis results a publication: ATL-PHYS-PUB-2019-043
The nominal Sherpa ttW sample is compared to its radiation uncertainty variations and the alternative generator. The ratio plots show the ratios of the alternative MC sample and scale variation to the nominal sample.
The fiducial cross sections, σgen = Agen × σgen, of the five regions for ttW analysis:
Distribution of the jet multiplicities and the scalar sum of jets transverse momentum, HTjets for the Region 1 with Nb−jets=1 selection requiring four and more jets:
