Non-resonant phenomena beyond the standard model in top-quark processesFaroughy Carías, Darius Alexander (Avtor) Kamenik, Jernej (Mentor) beyond the standard modeltop-quarkscollider physicsLHCnon-resonant new physicsnew physics in top quark physicseffective eld theorysimplifed modelsB-anomalieslepton flavor universality violationleptoquarksUV models.In this dissertation we analyze different non-resonant manifestations of physics beyond the Standard Model in the top-quark sector. We do this from a bottom up approach by proposing new observables and new search strategies for top-quark processes. By exploiting the different kinematical regimes of multi-resonance production at hadron colliders, we introduce a set of idealized cross-sections to characterize non-resonant New Physics (NP). We use these observables to study $pp \to t\bar{t}h$ production at the LHC and show how different effective operators of dimension-6 can be disentangled at the HL-LHC. Physics beyond the SM coupling exclusively to top-quarks is challenging to measure at the LHC, in particular, if the effects are not resonant. To address this we propose a complete search strategy for measuring SM rare $pp \to t\bar{t}t\bar{t}$ production at the 13 TeV LHC in the same-sign dilepton and the trilepton decay channels. We produce bounds demonstrating that a $3\sigma$ evidence measurement of $\sigma_{SM}(pp \to t\bar{t}t\bar{t})$ is accessible during Run-II and that a $5\sigma$ discovery of this process in the SM is possible. We also set limits on non-resonant BSM physics, in particular on the couplings of a top-philic mediator with masses below the top-pair production threshold. We argue that it is possible to have a UV completion for which $pp \to t\bar{t}t\bar{t}$ is a very powerful probe. Finally, we explore the possibility of top-philic NP producing deviations in $B$-meson decays. Inspired by the current deviations from lepton flavor universality in $b \to s\ell^+\ell^-$ at LHCb, we present an explanation based on top-philic NP. After analyzing the $B$-anomaly using effective theories, we classify all potential top-philic mediators and single out a Z’ and a two-leptoquark model $(\widetilde{U}_1 \sim (\bf{3},\bf{1},\rm{5/3})$ and $R_2 \sim (\bf{3},\bf{2},\rm{7/6}))$. We analyze these simplified models at the LHC and show that it can probe the relevant regions of parameter space. In the end, we construct a simple class of UV model living at the TeV scale that give rise to vector leptoquarks (that are SU(2)$_L$ singlets) as gauge bosons of SU(4) extensions of the SM. We use this construction to provide a UV complete model for the $\widetilde{U}_1$ and $R_2$ leptoquarks entering $b \to s$ transitions at the one-loop level.20192019-07-08 15:51:45Doktorsko delo/naloga108587VisID: 96123COBISS_ID: 3322980sl