arXiv subjects

Marc-Thomas Eisele

Publications and source records attributed to Marc-Thomas Eisele.

3 recordsLinked to original sources

arXiv2008

Leptogenesis With Many Neutrinos

We consider leptogenesis in scenarios with many neutrino singlets. We find that the lower bound for the reheating temperature can be significantly relaxed with respect to the hierarchical three neutrino case. We further argue that the upper bound for the neutrino mass scale from leptogenesis gets significantly lifted in these scenarios. As a specific realization, we then discuss an extra-dimensional model, where the large number of neutrinos is provided by Kaluza-Klein excitations.

hep-ph↗

arXiv2006

Family Symmetry and Single Right-Handed Neutrino Dominance in Five Dimensions

We consider several neutrino mass models in an extra-dimensional setting on a quantitative level. All the models are set in a five-dimensional scenario, with the standard model (SM) particles living on a brane, while three additional SM gauge singlets live in the bulk of an extra dimension, which is compactified on a S^1/Z_2 orbifold. The spontaneous breaking of an additional, continuous U(1) family symmetry is used to generate suitable neutrino mass matrices via single right-handed neutrino dominance through the corresponding five-dimensional extension of the see-saw mechanism. In this manner possible problems of this combination for some models in four dimensions could be overcome. The considered models differ with respect to the charges under the family symmetry and the nature of the five-dimensional Majorana mass term.

hep-ph↗

arXiv2006

Leptonic Dark Energy and Baryogenesis

We consider a baryogenesis scenario, where the difference of baryon (B) and lepton (L) number is conserved in such a way that the B-L asymmetry in the standard model sector is compensated by an asymmetry of opposite sign stored in the dark energy sector. Therefore, we introduce a toy-model in which a complex quintessence field carries a B-L asymmetry at late times. We determine the produced baryon asymmetry in the visible sector for a large range of initial conditions and find it easy to achieve a value of the observed order of magnitude. While the size of the produced baryon asymmetry depends on details of the underlying inflationary model, it turns out to be independent of the reheating temperature in many cases. We also discuss possible sources of instability like the formation of Q-Balls.

hep-ph↗