Fixed-order and merged parton-shower predictions for WW and WWj production at the LHC including NLO QCD and EW corrections

Abstract

First, we present a combined analysis of pp →μ+vμe−v¯e$$ \to {\mu}^{+}{v}{\mu }{\mathrm{e}}^{-}{\overline{v}}{\mathrm{e}} $$ and pp →μ+vμe−v¯ej$$ \to {\mu}^{+}{v}{\mu }{\mathrm{e}}^{-}{\overline{v}}{\mathrm{e}}\mathrm{j} $$ at next-to-leading order, including both QCD and electroweak corrections. Second, we provide all-order predictions for pp →μ+vμe−v¯e+$$ \to {\mu}^{+}{v}{\mu }{\mathrm{e}}^{-}{\overline{v}}{\mathrm{e}}+ $$jets using merged parton-shower simulations that also include approximate EW effects. A fully inclusive sample for WW production is compared to the fixed-order computations for exclusive zero- and one-jet selections. The various higher-order effects are studied in detail at the level of cross sections and differential distributions for realistic experimental set-ups. Our study confirms that merged predictions are significantly more stable than the fixed-order ones in particular regarding ratios between the two processes.