Towards global interpretation of LHC data: SM and EFT couplings from jet and top quark measurements at CMS

<!--HTML-->This thesis presents the first global interpretation of the measurements of double-differential cross sections of inclusive jet and top quark-antiquark pair ($t$$\bar{t}$) production in proton-proton collisions at the Large Hadron Collider (LHC) at the center of mass energy of $\sqrt{s}$ = 13 TeV, together with inclusive measurements in Deep Inelastic electron-proton Scattering (DIS) at HERA. The LHC data have been recorded by the Compact Muon Solenoid (CMS) experiment in 2016, and correspond to the integrated luminosity of 33.5 fb$^{-1}$ for inclusive jet measurement or 35.9 fb$^{-1}$ for the $t$$\bar{t}$ measurement.<br><br>This novel analysis is performed at next-to-leading order (NLO) of perturbative quantum chromodynamics (QCD), where the inclusive neutral and charged current DIS measurements at HERA, the CMS jet measurements and the normalized triple-differential cross sections of tt production are used together to constrain the parameters of QCD and impose constraints on new physics. In particular, the Standard Model Lagrangian is extended to incorporate effective contributions from quark contact interactions (CI). In this analysis, the constraints on the parton distributions, the strong coupling constant $\alpha$$_{S}$($m$$_{Z}$ and the top quark pole mass $m$$_{t}^{pole}$ are obtained and, simultaneously, limits on the scale $\Lambda$ of the CI are imposed. This results in $\alpha$$_{S}$($m$$_{Z}$) = 0.1188 $\pm$ 0.0031, $m$$_{t}^{pole}$ = 170.4 $\Lambda$ 0.7 GeV and the 95% confidence level limits of $\Lambda$ > 24 TeV for purely left-handed, $\Lambda$ > 32 TeV for vector-like and $\Lambda$ > 31 TeV for axial vector-like exchanges. For the first time, the LHC data are used for extracting the Wilson coefficient of the CI, unbiased from the assumptions on the Standard Model parameters.<br><br>The jet and top quark production at the LHC are further investigated individually, to determine the QCD parameters at highest precision. A Standard Model analysis is performed at next-to-next-to-leading order (NNLO) of perturbative QCD using the CMS jet cross section measurements together with the HERA DIS data. The parton distribution functions in the proton are extracted simultaneously with the strong coupling constant $\alpha$$_{S}$($m$$_{Z}$) = 0.1166 $\pm$ 0.0017. This the most precise single measurement of the strong coupling constant at the LHC, to date.<br><br>Further, the CMS measurements of the $t$$\bar{t}$ cross sections are used to extract the top quark mass in the MSR renormalisation scheme. In this scheme, the mass dependence in the difference of the pole and modified minimal subtraction ($\bar{M}{S}$) masses is replaced by a scale parameter $R$. The first study of the behaviour of the $R$ scale is presented. The extracted top quark MSR mass obtained using CMS measurements results in $m$$_{t}^{MSRn}$ ($R$ = 80 GeV) = 169.3$_{-0.7}^{+0.6}$ GeV, which is up to now the most precise value of the top quark MSRn mass extracted from experimental data.<br><br>The presented investigations of the fundamental couplings of the Standard Model, and of new physics, are at the edge of precision in experimental physics and high-energy phenomenology, paving the road towards a global interpretation of LHC data.