%0 Thesis
%A Mendizabal Morentin, Mikel
%T Z boson production in association with jets: measurement and phenomenology
%N DESY-THESIS-2024-001
%I Universität Hamburg
%V Dissertation
%C Hamburg
%M PUBDB-2024-00440
%M DESY-THESIS-2024-001
%B DESY-THESIS
%P 164
%D 2024
%Z Dissertation, Universität Hamburg, 2023
%X In this thesis, we study two Z boson production mechanisms: the Drell-Yan process andreal electroweak corrections.The transverse momentum spectrum of the Drell-Yan lepton pair is of general interest asit is sensitive to the hadron structure. Moreover, the small transverse momentum region, qT  <  m<sub>ll</sub>, is sensitive to the 3D structure of the hadron. To describe the qT  <  m<sub>ll</sub> region,resummation to all orders is needed. However, the qT m<sub>ll</sub> region is non-perturbativeand has to be modelled. This region is modelled via a Gaussian distribution of the intrinsictransverse momentum of the incoming partons. Nonetheless, this is insufficient, and verysoftgluon radiation is needed. We investigate the effect of very-soft gluon radiations in the qT ≪ m<sub>ll</sub> region within the Parton Branching framework, and how it relates to the Collins-Soper kernel of the TMD factorisation. The very-soft gluon radiation is removed throughthe soft-gluon resolution scale in the parton showers of Monte-Carlo event generators, such as PYTHIA8 and HERWIG7. We demonstrate that this leads to a centre-of-mass energydependent intrinsic transverse momentum, by tuning the intrinsic tranerse momentum. At high partonic centre-of-mass energies, electroweak corrections become large, and the Z boson might be produced as a real electroweak correction. In QCD processes, at highjet transverse momentum, virtual electroweak corrections become large, and at the TeV scale, their contribution to the cross-section is of the order of 10 %. We measure the contributionof real electroweak corrections to QCD events as a function of the jet transversemomentum. We analyse proton-proton collisions at a centre-of-mass energy of 13 TeV atthe LHC, recorded by the CMS experiment during 2016, corresponding to an integratedluminosity of 36.3 fb<sup>−1</sup>. We measure the contribution of the real electroweak correctionto a 1 TeV jet transverse momentum to be 1-2 %. Moreover, we investigate differentobservables sensitive to real electroweak corrections to test their modelling in differenttheoretical scenarios.
%F PUB:(DE-HGF)3 ; PUB:(DE-HGF)11
%9 BookDissertation / PhD Thesis
%R 10.3204/PUBDB-2024-00440
%U https://bib-pubdb1.desy.de/record/601967