The standard model allows for a successful description of most phenomena in particle physics. Since its inception by Glashow, Weinberg and Salam in the 1960ies, it has been confirmed in numerous experiments. However, there are fundamental limitations, such as for example the lack of any connection to gravity, no explanation for dark matter, the hierarchy problem, and the mass of neutrinos.
These difficulties triggered the development of many theories aiming to substitute or extend the standard model. Already in the 1970ies supersymmetry (SUSY) was proposed while searching for additional symmetries in particle physics, in particular between bosons and fermions. Thanks to its ability to solve many open questions in particle physics, SUSY is one of the most popular and best motivated theories beyond the standard model.
In our group we are primarily searching for the resonant production of supersymmetric particles in models with R-parity violation (RPV), leading to spectacular signatures in the CMS detector: electron+muon, electron+tau, muon+tau. Beyond RPV SUSY, such signatures can also occur in other theories beyond the standard model, in particular those involving charged lepton number violation; examples are the production of quantum black holes, and certain models predicting new heavy gauge bosons.
We also search for signs of RPV SUSY in events with same charge leptons (mu+mu+ etc.), which can occur in the production of supersymmetric partners of electron or muon.