In this thesis the electroweak production of the Z boson in association with twojets is investigated focusing on its topology via the Vector Boson Fusion (VBF)mechanism and the determination of heavy boson parton densities.The first part presents a theoretical study of the Drell–Yan and electroweak Zjj pro-duction mechanisms and their particle-level comparison, demonstrating the domi-nance of the former and motivating the definition of a VBF-enhanced phase space toisolate electroweak contributions. The impact of electroweak corrections is discussedas a motivation for introducing electroweak (heavy boson) densities. These densi-ties, derived from extended DGLAP evolution equations, are successfully validatedusing HERA DIS data and applied to VBF Z production to assess their relevancefor t-channel boson dynamics and future collider studies.The second part reports fiducial and differential cross-section measurements of Z-boson production with dijets in the Z ! e+e, Z ! μ+μ channels and the combi-nation of both, analysed within a common phase space. Both inclusive (QCD Zjj+ EW Zjj) and electroweak (EW Zjj) components are measured as functions ofthe dilepton transverse momentum, pllT . The inclusive measurement uses 59.83 fb1of 13 TeV CMS data from 2018, while the main result, the electroweak Zjj, exploitsthe full Run 2 dataset of 138 fb1 at ps = 13 TeV. The Run 2 electroweak Zjjmeasurement achieves a total precision of about 6%, establishing a new benchmarkfor EW Zjj studies
Keila Moral Figueroa (Mon,) studied this question.