B1c : Central Jets in Vector-Boson Scattering

Vector-boson scattering (VBS) and vector-boson fusion (VBF) at the LHC are accompanied by two jets, arising from scattered quarks. The lack of color exchange between the quarks, i.e. the peculiar color structure of VBS/VBF processes, results in suppressed hadronic/jet activity between these jets, which can be used for signal identification. We plan to calculate distributions for this hadronic activity at NLO QCD for various VBS/VBF and background processes, matched to the parton shower simulation of event generators. This will result in a precision tool for the study of VBS and VBF.

1. NLO QCD corrections for additional jet activity: NLO QCD corrections to VBF $V jjj$ production ($V = W, Z, \gamma$);NLO QCD corrections to VBS processes like $W +W +jjj$ or $W Zjjj$ production and QCD backgrounds; implementation in VBFNLO;
2. Interface to event generators: matching of NLO codes to parton shower programs within the Matchbox framework
3. Phenomenology of color flow observables: central jet veto strategies for VBF/VBS signal measurement; jet activity and particle flow as distinguishing features of VBF/VBS processes. Comparison with $V jjj$ and same sign W pair data. Precision assessment of these tools
4. Spinoffs: Dependence of VBS/VBF cross sections on tagging jet defini- tion/cone size beyond NLO QCD, comparison to scale uncertainties