Thermal right-handed neutrino production rate in the relativistic regime

Laine, Mikko Sakari (2013). Thermal right-handed neutrino production rate in the relativistic regime. Journal of High Energy Physics, 2013(8), pp. 1-34. Springer 10.1007/JHEP08(2013)138

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The production rate of right-handed neutrinos from a Standard Model plasma at a temperature above a hundred GeV is evaluated up to NLO in Standard Model couplings. The results apply in the so-called relativistic regime, referring parametrically to a mass M ~ πT, generalizing thereby previous NLO results which only apply in the non-relativistic regime M ≫ πT. The non-relativistic expansion is observed to converge for M ≳ 15T, but the smallness of any loop corrections allows it to be used in practice already for M ≳ 4T. In the latter regime any non-covariant dependence of the differential rate on the spatial momentum is shown to be mild. The loop expansion breaks down in the ultrarelativistic regime M ≪ πT, but after a simple mass resummation it nevertheless extrapolates reasonably well towards a result obtained previously through complete LPM resummation, apparently confirming a strong enhancement of the rate at high temperatures (which facilitates chemical equilibration). When combined with other ingredients the results may help to improve upon the accuracy of leptogenesis computations operating above the electroweak scale.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Institute of Theoretical Physics
10 Strategic Research Centers > Albert Einstein Center for Fundamental Physics (AEC)

UniBE Contributor:

Laine, Mikko Sakari

Subjects:

500 Science > 530 Physics

ISSN:

1029-8479

Publisher:

Springer

Language:

English

Submitter:

Esther Fiechter

Date Deposited:

05 Jun 2014 16:24

Last Modified:

17 Sep 2015 11:16

Publisher DOI:

10.1007/JHEP08(2013)138

BORIS DOI:

10.7892/boris.42217

URI:

https://boris.unibe.ch/id/eprint/42217

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