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arXiv · 2108.07826

On improving NLO merging for $t \bar t W$ production

Rikkert Frederix·Ioannis Tsinikos
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Abstract

We introduce an improvement to the FxFx matrix element merging procedure for $pp\to t \bar t W$ production at NLO in QCD with one and/or two additional jets. The main modification is an improved treatment of jets that are not logarithmically enhanced in the low transverse-momentum regime. We provide predictions for the inclusive cross section and the $t \bar t W$ differential distributions including parton-shower effects. Taking also the NLO EW corrections into account, this results in the most-accurate predictions for this process to date. We further proceed to include the on-shell LO decays of the $t \bar t W$ including the tree-level spin correlations within the narrow-width approximation, focusing on the multi-lepton signatures studied at the LHC. We find a $\sim\!\!30\%$ increase over the NLO QCD prediction and large non-flat $K$-factors to differential distributions.

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Rikkert Frederix, Ioannis Tsinikos. 2021-08-17. On improving NLO merging for $t \bar t W$ production. https://doi.org/10.1007/jhep11(2021)029

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