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arXiv · 2212.05349

On different approaches to freeze-in and freeze-out leptogenesis with quasi-degenerate neutrinos

J. Racker
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Abstract

We compare two approaches for determining the generation of lepton asymmetry during production and decay of quasi-degenerate neutrinos, namely the density matrix formalism and a recent proposal which does not involve any counting of neutrino number densities and is based on plugging the resummed propagator in a quantum field theory model for neutrino oscillations. We show numerically and analytically that they are almost equivalent except in the limit of very large mass splittings. The comparison, performed in a simple scalar toy model, helps to understand several issues that have been discussed in the literature.

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J. Racker. 2022-12-10. On different approaches to freeze-in and freeze-out leptogenesis with quasi-degenerate neutrinos. https://doi.org/10.1140/epjc/s10052-023-11321-4

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