Fixed-order and merged parton-shower predictions for WW and WWj production at the LHC including NLO QCD and EW corrections
Stephan Bräuer, Ansgar Denner, Mathieu Pellen, Marek Schönherr, Steffen Schumann
Abstract
A bstract First, we present a combined analysis of pp $$ \to {\mu}^{+}{v}_{\mu }{\mathrm{e}}^{-}{\overline{v}}_{\mathrm{e}} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mo>→</mml:mo> <mml:msup> <mml:mi>μ</mml:mi> <mml:mo>+</mml:mo> </mml:msup> <mml:msub> <mml:mi>v</mml:mi> <mml:mi>μ</mml:mi> </mml:msub> <mml:msup> <mml:mi>e</mml:mi> <mml:mo>−</mml:mo> </mml:msup> <mml:msub> <mml:mover> <mml:mi>v</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> <mml:mi>e</mml:mi> </mml:msub> </mml:math> and pp $$ \to {\mu}^{+}{v}_{\mu }{\mathrm{e}}^{-}{\overline{v}}_{\mathrm{e}}\mathrm{j} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mo>→</mml:mo> <mml:msup> <mml:mi>μ</mml:mi> <mml:mo>+</mml:mo> </mml:msup> <mml:msub> <mml:mi>v</mml:mi> <mml:mi>μ</mml:mi> </mml:msub> <mml:msup> <mml:mi>e</mml:mi> <mml:mo>−</mml:mo> </mml:msup> <mml:msub> <mml:mover> <mml:mi>v</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> <mml:mi>e</mml:mi> </mml:msub> <mml:mi>j</mml:mi> </mml:math> at next-to-leading order, including both QCD and electroweak corrections. Second, we provide all-order predictions for pp $$ \to {\mu}^{+}{v}_{\mu }{\mathrm{e}}^{-}{\overline{v}}_{\mathrm{e}}+ $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mo>→</mml:mo> <mml:msup> <mml:mi>μ</mml:mi> <mml:mo>+</mml:mo> </mml:msup> <mml:msub> <mml:mi>v</mml:mi> <mml:mi>μ</mml:mi> </mml:msub> <mml:msup> <mml:mi>e</mml:mi> <mml:mo>−</mml:mo> </mml:msup> <mml:msub> <mml:mover> <mml:mi>v</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> <mml:mi>e</mml:mi> </mml:msub> <mml:mo>+</mml:mo> </mml:math> 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.