Lepton asymmetry from mixing and oscillations

Kartavtsev, Alexander; Millington, Peter; Vogel, Hendrik

Abstract

We show how the two physically-distinct sources of CP-asymmetry relevant to scenarios of leptogenesis: (i) resonant mixing and (ii) oscillations between different flavours can be unambiguously identified within the Kadanoff-Baym formalism. These contributions are isolated by analyzing the spectral structure of the non-equilibrium propagators without relying on the definition of particle number densities. The mixing source is associated with the usual mass shells, whereas the oscillation source is identified with a third intermediate shell. In addition, we identify terms lying on the oscillation shell that can be interpreted as the destructive interference between mixing and oscillation. We confirm that identical shell structure is obtained in both the Heisenberg- and interaction-picture realizations of the Kadanoff-Baym formalism. In so doing, we illustrate the self-consistency and complementarity of these two approaches. The interaction-picture approach in particular has the advantage that it may be used to analyze all forms of mass spectra from quasi-degenerate through to hierarchical.

Citation

Kartavtsev, A., Millington, P., & Vogel, H. (2016). Lepton asymmetry from mixing and oscillations. Journal of High Energy Physics, 2016(6), Article 66. https://doi.org/10.1007/JHEP06%282016%29066

• Journal Article Type: Article
• Acceptance Date: Apr 11, 2016
• Online Publication Date: Jun 10, 2016
• Publication Date: Jun 10, 2016
• Deposit Date: Nov 2, 2017
• Publicly Available Date: Nov 2, 2017
• Journal: Journal of High Energy Physics
• Electronic ISSN: 1029-8479
• Publisher: Springer Verlag
• Peer Reviewed: Peer Reviewed
• Volume: 2016
• Issue: 6
• Article Number: 66
• DOI: https://doi.org/10.1007/JHEP06%282016%29066
• Keywords: Thermal field theory; Effective field theories
• Public URL: https://nottingham-repository.worktribe.com/output/795706
• Publisher URL: https://link.springer.com/article/10.1007%2FJHEP06%282016%29066
• Contract Date: Nov 2, 2017