Physics of the Standard Model and Beyond
Principal investigator
In high energy particle physics it is widely believed that the energy frontier experiments at LHC and the planned linear colliders, ILC and/or CLIC, together with ongoing and new experiments in neutrino and flavour physics will unravel fundamental problems in particle and astroparticle physics. A prerequisite for this progress is the complete understanding of the Standard model (SM) predictions. One of the triumphs of SM physics has been the extent to which QCD successfully describes strong interaction processes observed at colliders. More accurate QCD calculations are nowadays essential in understanding the enormous amount of available high-precision data, particularly since new physics effects are obscured by standard QCD processes. Our focus in that area will be to improve the description of hard exclusive processes by including higher-order contributions and by further developing the corresponding methods for automatic QCD calculations. Furthermore, we plan to do precision studies of top-quark production and decay observables which provide a unique view to the mechanism of electroweak symmetry breaking, important for understanding of particle mass generation. In the top-quark decay the information about its spin polarization imprinted by the production process is preserved, and can be calculated and measured in angular distributions of decay products providing other way to search for deviations from the SM expectations. Regarding new physics, the fact that neutrinos have a mass already requires an extension of the SM and calls for an understanding of the origin of neutrino masses. The seesaw mechanism, included in a theory as the one where left-right symmetry (parity) is restored at accessible LHC energies, stands out as a prominent theoretical candidate, and this theory links the origin of neutrino masses to new interactions at high energies and to the restoration of parity. A phenomenological investigation of these predictions is thus compelling and timely.