Precision study of GeV-scale resonant leptogenesis

Ghiglieri, Jacopo; Laine, Mikko Sakari (2019). Precision study of GeV-scale resonant leptogenesis. Journal of High Energy Physics, 2019(2) Springer 10.1007/JHEP02(2019)014

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Low-scale leptogenesis is most efficient in the limit of an extreme mass degeneracy of right-handed neutrino flavours. Two variants of this situation are of particular interest: large neutrino Yukawa couplings, which boost the prospects of experimental scrutiny, and small ones, which may lead to large lepton asymmetries surviving down to T < 5 GeV. We study benchmarks of these cases within a “complete” framework which tracks both helicity states of right-handed neutrinos as well as their kinetic non-equilibrium, and includes a number of effects not accounted for previously. For two right-handed flavours with GeV-scale masses, Yukawa couplings up to |h| ~0.7×10⁻⁵ are found to be viable for baryo- genesis, with ∆M/M ~10⁻8 as the optimal degeneracy. Late-time lepton asymmetries are most favourably produced with ∆M/M ~10⁻¹¹. We show that the system reaches a stationary state at T < 15 GeV, in which lepton asymmetries can be more than 103 times larger than the baryon asymmetry, reach flavour equilibrium, and balance against helicity asymmetries.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Institute of Theoretical Physics

UniBE Contributor:

Ghiglieri, Jacopo and Laine, Mikko Sakari

Subjects:

500 Science > 530 Physics

ISSN:

1029-8479

Publisher:

Springer

Language:

English

Submitter:

Esther Fiechter

Date Deposited:

14 May 2019 13:18

Last Modified:

23 Oct 2019 20:13

Publisher DOI:

10.1007/JHEP02(2019)014

ArXiv ID:

1811.01971

BORIS DOI:

10.7892/boris.127982

URI:

https://boris.unibe.ch/id/eprint/127982

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