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 $$ \to {\mu}^{+}{v}_{\mu }{\mathrm{e}}^{-}{\overline{v}}_{\mathrm{e}} $$ → μ + v μ e − v ¯ e and pp $$ \to {\mu}^{+}{v}_{\mu }{\mathrm{e}}^{-}{\overline{v}}_{\mathrm{e}}\mathrm{j} $$ → μ + v μ e − v ¯ e j at next-to-leading order, including both QCD and electroweak corrections. Second, we provide all-order predictions for pp $$ \to {\mu}^{+}{v}_{\mu }{\mathrm{e}}^{-}{\overline{v}}_{\mathrm{e}}+ $$ → μ + v μ e − v ¯ 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.

NNLO QCD predictions for W+c-jet production at the LHC

“…[69] has been checked against Recola [74,75] at tree and one-loop level and the evaluation of the harmonic polylogarithms using Ginac has been checked against the libraries hplog [76] and tdhpl [77]. Finally, the LO and NLO QCD predictions for W + j c have been successfully compared against an independent Monte Carlo program, MoCaNLO+Recola which has already been used in several V+jets computations [78][79][80][81][82][83][84][85][86]. This last check also validates the implementation of the event selection as well as the correct use of the flavored jet algorithm up to NLO QCD accuracy.…”

NLO QCD and EW corrections to vector-boson scattering into ZZ at the LHC

“…It has also been successfully compared for WZ scattering with results of BONSAY+OPENLOOPS [18] and for same-sign W scattering with the combination of Recola and the Monte Carlo integration code BBMC [17]. MoCaNLO+Recola has also served as baseline for the validation of the implementation of O α 7 corrections in Powheg+Recola [19] for same-sign W scattering and of O α s α 5 corrections for pp → WWj in Sherpa+Recola [46,47]. For VBS into ZZ, we compared the dominant partonic process ud → e + e − µ + µ − ud as well as the channels us → e + e − µ + µ − dc, uu → e + e − µ + µ − uu, and uc → e + e − µ + µ − ds at order O α 7 and selected contributions at order O α s α 6 between MoCaNLO+Recola and BBMC+Recola and found agreement within integration errors.…”

Vector bosons and jets at the LHC

“…In Ref. [5], theoretical predictions to address such a measurement have been presented. They have been obtained with the fully automated framework S +R [6][7][8].…”

“…Note that in all theoretical predictions presented in Ref. [5], a jet veto has been applied following the experimental set-up. In Fig.…”