%0 Thesis %A Dominguez Damiani, Daniela %T Cross Section measurements of t―t pair production in the boosted regime in proton-proton collisions at √s=13 TeV with the CMS experiment at the Large Hadron Collider %N DESY-THESIS-2020-006 %I Universität Hamburg %V Dissertation %C Hamburg %M PUBDB-2020-02131 %M DESY-THESIS-2020-006 %B DESY-THESIS %P 274 %D 2020 %Z Dissertation, Universität Hamburg, 2019 %X In this thesis measurements of the t―t pair production at the very high transverse momentum are presented. When a top quark is produced with very high momentum the decay products are collimated in the direction of the quark, and they can be clustered within a single large cone size jet. The decay products of top quarks with transverse momentum larger than 400 GeV are likely having this boosted configuration. A definition of a particle-level top jet is developed which is independent of the partonic configuration. The measurements are performed with proton-proton collision data collected by the CMS experiment at the LHC, at the center of mass energy of √s=13 TeV and they are presented differentially in the transverse momentum of the top jets and differentially in the azimuthal angle ∆ϕ between the two top-jets. The results are compared to theory predictions provided from different Monte Carlo event generators: i.e Powheg+Pythia8, Powheg+Herwigpp and aMC@NLO+Pythia8. %F PUB:(DE-HGF)3 ; PUB:(DE-HGF)11 %9 BookDissertation / PhD Thesis %R 10.3204/PUBDB-2020-02131 %U https://bib-pubdb1.desy.de/record/438672