Dynamical approach to MPI in W+dijet and Z+dijet production within the PYTHIA event generator

The new numerical approach that includes 1⊗ 2 mechanisms is applied to double parton scattering (DPS) in W+dijet and Z+dijet final-state production in proton–proton collisions at the LHC. By using the underlying event (UE) simulation from a pythia 8.205 tune extracted in hadronic events, we show that, like in the case of a four-jet final state, the inclusion of 1⊗ 2 mechanisms improves the description of experimental data measured at 7 TeV. The analysis is based on applying an event-by-event reweighting factor to a standard pythia 8.205 sample, by using the theoretical value of σ _eff , which includes corrections due to 1⊗ 2 mechanisms. In addition, predictions for proton–proton collisions at a center-of-mass energy of 13 TeV are shown for DPS-sensitive observables. The relevant code, used for this analysis, is publicly available at the following link: http://desy.de/ gunnep/SigmaEffectiveDependence/ .