  In these proceedings we discuss the family of Vector Boson Scattering (VBS)
processes, in particular we look at a very recent result from the CMS
collaboration where a search was performed for VBS in the four-lepton and
two-jet final state using proton-proton collisions at 13 TeV. The electroweak
production of two Z bosons in association with two jets was measured with an
observed (expected) significance of 2.7 (1.6) standard deviations, using a
multivariate classifier. Additionally an expected significance of 1.2 standard
deviations was found using matrix elements techniques. In this work we discuss
the latter approach in detail.
