Leptogenesis in Non-Equilibrium Quantum Field Theory

• Applicant: Professor Dr. Björn Garbrecht
• Subject Area: Nuclear and Elementary Particle Physics, Quantum Mechanics, Relativity, Fields
• Term: from 2011 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 203737337

Leptogenesis is one of the most plausible explanations for the emergence of the asymmetry betweenmatter and anti-matter in the Early Universe. Besides, interesting links to the phenomenology of neutrino oscillations can be established. The theoretical description of Leptogenesis requires the consistent calculation of interaction rates of elementary particles within a background of finite particle number densities. A good method for treating such a problem of non-equilibrium Quantum Field Theory is given by the Closed-Time-Path (CTP) formalism. We apply the CTP formalism in order to systematically derive kinetic equations, that describe Leptogenesis, from first principles of Quantum Field Theory. Building on this, we will include important additonal corrections, namely finite-temperature effects and flavour-coherence and -oscillations, in our calculations. We will summarise our results within a computer code, that can be used for routine parametric studies of the lepton asymmetry. An important application will be the improvement of lower bounds on the temperature, at which Leptogenesis can take place.

• DFG Programme: Research Grants