Thorsten Feldmann

TP1 Research Group – Prof. Dr. Thorsten Feldmann

The main focus of our research is to better understand the theoretical background that underlies the concept of “Flavour”, i.e. the presence of different quarks and leptons in nature, organized in three “families/generations” with very hierarchical mass patterns and non-generic inter-generational transition strengths, encoded in terms of “mixing angles”. This involves different theoretical and phenomenological aspects which are investigated in our group:

  • The phenomenology of Rare Flavour Transitions, in particular for heavy bottom (and also charm) quarks.
    These transitions are currently studied with increasing sensitivity by means of dedicated experiments at high-energy particle colliders (“B-factories”, LHC, …). For a reliable interpretation of the experimental data, we provide detailed analyses on how to quantify and control theoretical input parameters and their uncertainties.
  • Theoretical predictions for heavy-quark decays on the basis of systematic calculations for quantum corrections from the strong interactions, using “Effective Field Theory Methods” in “Quantum Chromodynamics” (QCD).
    In particular, we study the separation (“factorization”) of short- and long-distance quantum fluctuations for energetic particles by means of “Soft-collinear effective theory” (SCET).
  • Classification of “Flavour Symmetries and their breaking within the “Standard Model” of particle physics or its possible extensions (“New Physics Models”).
    On the one hand, this might shed new light on the origin of the observed flavour hierarchies. On the other hand, this helps to systematically classify new sources of flavour transitions from possible physics beyond the Standard Model.