Related papers: Leptogenesis at Low Scale
We consider a model of baryogenesis based on adding lepton number-violating quadratic mass terms to the inflaton potential of a non-minimally coupled inflation model. The $L$-violating mass terms generate a lepton asymmetry in a complex…
In supersymmetric models with lepton-number violation, hence also R-parity violation, it is easy to have realistic neutrino masses, but then leptogenesis becomes difficult to achieve. After explaining the general problems involved, we study…
Baryogenesis via leptogenesis provides an appealing mechanism to explain the observed baryon asymmetry of the Universe. Recent refinements in the understanding of the dynamics of leptogenesis include detailed studies of the effects of…
I propose a new mechanism for baryogenesis, in which the out-of-equilibrium condition is not neccessary. When the electroweak symmetry is broken spontaneously, left-handed neutrinos may get Majorana masses containing $CP-$violating phases.…
The gravitino problem gives a severe constraint on the thermal leptogenesis scenario. This problem leads us to consider some alternatives to it if we try to keep the gravitino mass around the weak scale $m_{3/2} \sim 100$ GeV. We consider,…
A non-supersymmetric renormalizable $SO(10)$ model is investigated for its viability in explaining the observed fermion masses and mixing parameters along with the baryon asymmetry produced via thermal leptogenesis. The Yukawa sector of the…
The effects of the lightest neutrino mass in ``flavoured'' leptogenesis are investigated in the case when the CP-violation necessary for the generation of the baryon asymmetry of the Universe is due exclusively to the Dirac and/or Majorana…
We investigate a resonant leptogenesis scenario by quasi-degenerate right-handed neutrinos which have TeV-scale masses. Especially, we consider the case when two right-handed neutrinos are responsible to leptogenesis and the seesaw…
Thermal leptogenesis in the canonical seesaw model in supersymmetry suffers from the incompatibility of a generic lower bound on the mass scale of the lightest right-handed neutrino and the upper bound on the reheating temperature of the…
We show that the leptogenesis is automatic within the supersymmetric standard model if there exist right-handed neutrinos with mass less than $H_{\it inf}$, the expansion rate during the inflation. Its scalar component grows during the…
We consider an extended version of superconformal subcritical hybrid inflation model by introducing three right-handed neutrinos that have the Majorana mass terms. In the model one of the right-handed sneutrinos plays a role of the inflaton…
Among the mechanisms which successfully explain the generation of the Baryon Asymmetry of the Universe, Leptogenesis through right-handed neutrino decays is especially attractive. Unfortunately, this theory suffers from a lack of…
We discuss the possibility of light scalar dark matter generated by right-handed neutrino in a $L_{\mu}-L_{\tau}$ model, in which the dark matter $\phi_{dm}$ carries $U(1)_{L_{\mu}-L_{\tau}}$ charge but it is a singlet in the Standard…
Leptogenesis, i.e. the creation of a lepton asymmetry in the early Universe, may occur through the decay of heavy singlet (right-handed) neutrinos. If we require it not to be erased by physics beyond the Standard Model at the TeV energy…
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…
It is well known that the leptogenesis mechanism offers an attractive possibility to explain the baryon asymmetry of the universe. Its particular robustness however comes with one major difficulty: it will be very hard if not impossible to…
In this talk, I present a novel and minimal alternative to thermal leptogenesis, which builds upon the assumption that the electroweak gauge bosons are coupled to an axion-like scalar field, as it is, for instance, the case in certain…
The simplest possibility to explain the baryon asymmetry of the Universe is to assume that radiation is created asymmetrically between baryons and anti-baryons after the inflation. We propose a new mechanism of this kind where CP-violating…
We present a complete computation of the inflaton decay into very massive fermions during preheating. We show that heavy fermions are produced very efficiently up to masses of order 10^{17}-10^{18} GeV; the accessible mass range is thus…
We investigate a non-instantaneous reheating period in the early Universe, where the inflaton field decays exclusively to right-handed neutrinos (RHNs). The subsequent decay of these RHNs into Standard Model particles not only drives the…