Related papers: Leptogenesis from composite singlets
For supersymmetric theories with gravitino dark matter, the maximal reheating temperature consistent with big bang nucleosynthesis bounds arises when the physical gaugino masses are degenerate. We consider the cases of a stau or sneutrino…
Supersymmetric scenarios where the lightest superparticle (LSP) is the gravitino are an attractive alternative to the widely studied case of a neutralino LSP. A strong motivation for a gravitino LSP arises from the possibility of achieving…
We study leptogenesis in supersymmetric SO(10) models with a left-right symmetric seesaw mechanism, including flavour effects and the contribution of the next-to-lightest right-handed neutrino. Assuming M_D = M_u and hierarchical light…
We study the reheating and non-thermal leptogenesis in the case of a vector inflaton. We concentrate on particle production during the phase of oscillating background, especially gravitational production induced by the presence of…
Considering gravitino dark matter scenarios, we study constraints on the reheating temperature of inflation. We present the gauge-invariant result for the thermally produced gravitino yield to leading order in the Standard Model gauge…
Leptogenesis constitues a very simple scenario to achieve the baryon asymmetry that we observe today. It requires only the presence of right handed neutrinos (which arise very naturally in many extensions of the Standard Model) and depends…
We review the status of thermal leptogenesis in the minimal $SU(5)\times U(1)$ and $SO(10)$ unified models under the assumption that the leptonic asymmetry generated in the out-of-equilibrium decays of heavy Majorana neutrinos (and its…
Upper bounds on the CP asymmetry relevant for leptogenesis are reexamined and found weaker than in previous literature, both for hierarchical and for quasi-degenerate right-handed neutrinos. Successful leptogenesis implies the usual lower…
We propose a new leptogenesis scenario in which the lepton asymmetry and matter particles are simultaneously generated due to the coherent oscillating Higgs background. To demonstrate the possibility of our scenario, we consider the type-I…
We extend the results of a previous analysis of ours showing that, when both heavy and light flavour effects are taken into account, successful minimal (type I + thermal) leptogenesis with SO(10)-inspired relations is possible. Barring fine…
Leptogenesis induced by the oscillations of GeV-scale neutrinos provides a minimal and testable explanation of the baryon asymmetry of the Universe. In this work we extend previous studies invoking only two heavy neutrinos to the case of…
We study the prediction for leptogenesis in two renormalizable supersymmetric $SO(10)\times A_4$ modular models in which the neutrino mass is dominantly generated by the type I seesaw mechanism. The evolution of the lepton asymmetries are…
Successful Soft Leptogenesis (SL) requires a relatively low mass scale for the SU(2) singlet neutrinos of $10^5-10^8$ GeV. However, conventional SL (unflavoured) requires an unnaturally small soft supersymmetry(SUSY)-breaking bilinear $B…
We discuss resonant leptogenesis arising from the decays of two nearly-degenerate right-handed neutrinos, identified as the inflaton and stabiliser superfields in a model of chaotic sneutrino inflation. We compare an analytical estimate of…
The left-right symmetric model with doublet and bi-doublet Higgs scalars can accommodate linear, inverse or double seesaw for generating small neutrino masses in the presence of three singlet fermions. If the singlet fermions have small…
We present a general description of the problems encountered when attempting to build a simple model of leptogenesis and hence of baryogenesis at an energy scale as low as 1-10 TeV. We consider three possible lepton asymmetry enhancement…
It has been proposed that two resonances could coincide in the early universe at temperatures $T \sim 0.2 ... 0.5$ GeV: one between two nearly degenerate GeV-scale sterile neutrinos, producing a large lepton asymmetry through freeze-out and…
We revisit the thermal leptogenesis scenario in the type-I seesaw framework featuring three heavy Majorana neutrinos with a hierarchical mass spectrum. We focus on low energy observables, specifically the lightest neutrino mass…
We study the production of spin 1/2 gravitinos in a thermal Universe. Taking into account supersymmetry breaking due to the finite thermal energy density of the Universe, there is a large enhancement in the cross section of production of…
We consider a simple extension of the standard model, which could give a solution to its $CP$ issues through both the Peccei-Quinn mechanism and the Nelson-Barr mechanism. Its low energy effective model coincides with the scotogenic model…