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arXiv · 1202.1288

Thermal production of ultrarelativistic right-handed neutrinos: Complete leading-order results

Denis Besak·Dietrich Bodeker
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Abstract

The thermal production of relativistic right-handed Majorana neutrinos is of importance for models of thermal leptogenesis in the early Universe. Right-handed neutrinos can be produced both by 1 <-> 2 decay or inverse decay and by 2 -> 2 scattering processes. In a previous publication, we have studied the production via 1 <-> 2 (inverse) decay processes. There we have shown that multiple scattering mediated by soft gauge boson exchange also contributes to the production rate at leading order, and gives a strong enhancement. Here we complete the leading order calculation by adding 2 -> 2 scattering processes involving either electroweak gauge bosons or third-generation quarks. We find that processes with gauge interactions give the most important contributions. We also obtain a new sum rule for the Hard Thermal Loop resummed fermion propagator.

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Denis Besak, Dietrich Bodeker. 2015-04-27. Thermal production of ultrarelativistic right-handed neutrinos: Complete leading-order results. https://doi.org/10.1088/1475-7516%2F2012%2F03%2F029

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