We present the computation of the differential cross section for the process p p (formula presented) → (W+ W− b (formula presented) →) e+νeμ− (formula presented) μ b (formula presented) + X at NLO QCD accuracy matched to Shower Monte Carlo (SMC) simulations using PowHel, on the basis of the interface between HELAC-NLO and POWHEG-BOX. We include all resonant and non-resonant contributions. This is achieved by fully taking into account the effect of off-shell t-quarks and off-shell W-bosons in the complex mass scheme. We also present a program called DECAYER that can be used to let the t-quarks present in the event files for p p (formula presented) X processes decay including both the finite width of the t-quarks and spin correlations. We present predictions for both the Tevatron and the LHC, with emphasis on differences emerging from three different W+ W− b (formula presented) hadroproduction computations: (i) full implementation of the p p (formula presented) → W+ W− b (formula presented) process, (ii) generating on-shell t-quarks pushed off-shell with a Breit-Wigner finite width and decayed by Decayer, and (iii) on-shell t-quark production followed by decay in the narrow width approximation, as described by the SMC.
- Hadronic Colliders
- NLO Computations
ASJC Scopus subject areas
- Nuclear and High Energy Physics