Phenomenology of baryogenesis from lepton-doublet mixing

Abstract

Mixing lepton doublets of the Standard Model can lead to lepton flavour asymmetries in the Early Universe. We present a diagrammatic representation of this recently identified source of CP violation and elaborate in detail on the correlations between the lepton flavours at different temperatures. For a model where two sterile right-handed neutrinos generate the light neutrino masses through the see-saw mechanism, the lower bound on reheat temperatures in accordance with the observed baryon asymmetry turns out to be 1.2 × 10 9 GeV. With three right-handed neutrinos, substantially smaller values are viable. This requires however a tuning of the Yukawa couplings, such that there are cancellations between the individual contributions to the masses of the light neutrinos.

Why is there more matter than antimatter? Calculational methods for leptogenesis and electroweak baryogenesis

“…One exception, where we go into more particular detail, is the discussion on resonant leptogenesis, where the CTP methods establish the connection between decay asymmetries from S-matrix elements and those computed from the oscillations of the RHNs, thus leading to an accurate calculation of the asymmetry produced in the mass-degenerate regime. Nonetheless, also that discussion may be generalized to other scenarios relying on the mixing of almost mass-degenerate states [120][121][122]. Moreover, in Section 8, we draw some parallels with electroweak baryogenesis, such that resonant leptogenesis seems to be a fitting topic within the present review.…”

Primordial lepton oscillations and baryogenesis

“…/H describes the flavor-dependent wash-out effects. The number density of the inflaton is 9) and the splitting of the dispersion relation is…”

Baryogenesis via particle-antiparticle oscillations

“…In Section III we study the oscillations of an electroweak scale pseudo-Dirac fermion in the early Universe (at temperature T ∼ O(10 − 100 GeV)). We include interactions, specifically elastic scatterings with light particles and an- 3 For studies of quantum decoherence effects in flavor oscillations in resonant leptogenesis, see, e.g., [21][22][23][24] 4 As a way to evade all quantum decoherence effects, the authors of Ref. [27] used heavy particles that decay out-of-equilibrium at very low temperatures to mesinos.…”

“…For studies of quantum decoherence effects in flavor oscillations in resonant leptogenesis, see, e.g.,[21][22][23][24] 4 As a way to evade all quantum decoherence effects, the authors of Ref [27]. used heavy particles that decay out-of-equilibrium at very low temperatures to mesinos.…”