Fragmentation and Jet Substructure in Heavy Flavour Processes

Heavy flavours, i.e. quarks with masses larger than the mass of the proton, play a fundamental role in advancing our understanding of the Standard Model as they provide unique insights on electroweak symmetry breaking and the Higgs mechanism. This PhD thesis focuses on the bottom and charm quarks, considering two key aspects of heavy flavour physics. In the first part, we analyze the energy spectrum of heavy flavours in the regime where the emitted colour radiation becomes soft and collinear. Specifically, we investigate how to systematically account for these effects to all orders in perturbation theory, while accurately incorporating the mass effects of the radiating heavy flavour. In the second part of this thesis, we investigate jet substructure observables that are sensitive to the so-called dead-cone effect, which refers to the suppression of QCD radiation around heavy quarks. Building upon the computational framework developed in the first part of the thesis, we will use it to make theoretical predictions for heavy flavour jets and compare our results with Monte Carlo simulations.