arXiv subjects
Publications and source records attributed to Rhea Moutafis.
We describe the automation of the calculation of perturbative unitarity constraints including scalars that have colour charges, and its release in SARAH 4.14.4. We apply this, along with vacuum stability constraints, to a simple dark matter model with colourful mediators and interesting decays, and show how it leads to a bound on a thermal relic dark matter mass well below the classic Griest-Kamionkowski limit.
A global analysis of the Standard Model Effective Field Theory (SMEFT) with SFitter is performed using measurements of single top quark production and top quark decay processes from ATLAS and CMS at center-of-mass energies of 7, 8 and 13 TeV. NLO QCD corrections are included in the theoretical predictions of all involved processes. Correlations among theoretical and experimental uncertainties are accounted for using DataPrep, which has been developed by the author. Using the dataset prepared by this software, constraints for the relevant degrees of freedom are derived. Almost all constraints are more than three times more stringent than the values of the literature. This thesis sets the technical and conceptual framework for a global fit of the entire top quark and Higgs boson sectors, which the author is involved in. The project marks an important milestone towards a truly global analysis constraining physics beyond the Standard Model in a model-independent way.
Searches for invisible Higgs decays in weak boson fusion are a well-known laboratory for jets and QCD studies. We present a series of results on tagging jets and central jet activity. First, precision analyses of the central jet activity require full control of single top production in some analyses. Second, the rate dependence on the size of the tagging jets is not limited to weak boson fusion. For the first time, we show how subjet information on the tagging jets and on the additional jet activity can be used to extract the Higgs signal. The additional observables relieve some of the pressure on other, critical observables. Finally, we compare the performance of weak boson fusion and associated Higgs production.