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Dirac neutrinos with lepton-number-violating interactions can give rise to a new leptogenesis mechanism. In its simplest renormalizable realization, based on a gauged B-L symmetry spontaneously broken by four units, the decay of a new…
Baryogenesis via leptogenesis is an attractive scenario that links the physics of right handed neutrino sector with the low energy neutrino data. In the light of current neutrino oscillation data we studied the bound on the mass scale…
Leptogenesis is an attractive scenario for the generation of the baryon asymmetry of the Universe that relies on the dynamics of right-handed neutrinos (RHNs) in the seesaw extension of the Standard Model. In standard thermal leptogenesis,…
We consider a type-I seesaw framework with a flavour symmetry from the series of non-abelian groups $\Delta (3 n^2)$ and $\Delta (6 n^2)$ and a CP symmetry. Breaking these symmetries non-trivially results in the right-handed neutrinos being…
The inverse seesaw (ISS) model provides an attractive framework that can naturally explain the smallness of neutrino masses while accommodating some sterile neutrinos potentially accessible at present or future experiments. However, in…
Standard thermal leptogenesis in the type-I seesaw model requires very heavy right-handed neutrinos (RHNs). This makes it hard to probe this scenario experimentally and results in large radiative corrections to the Higgs boson mass. In this…
We study leptogenesis in the quasi-degenerate but non-resonant regime. Expanding the CP asymmetry parameter near degeneracy and imposing the conservative non-resonance condition that the mass splitting must be much greater than the…
We analyze leptogenesis in gauge extensions of the Standard Model with keV sterile neutrino dark matter. We find that both the observed dark matter abundance and the correct baryon asymmetry of the Universe can simultaneously emerge in…
We consider a generic type of leptogenesis model which can successfully produce the correct value of the observed baryon number to entropy ratio. The main feature of this model is that it is a simple TeV scale model, a scale accessible in…
We present a class of leptogenesis models where the light neutrinos acquire their observed mass through a symmetry-motivated construction. We consider an extension of the Standard Model, which includes three singlet neutrinos which have…
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…
The conventional seesaw-leptogenesis can simultaneously explain the suppression of neutrino masses and the generation of cosmic baryon asymmetry, but usually cannot predict an unambiguous relation between these two sectors. In this work we…
In this work we use previous results on the masses and mixing of neu- trinos of an S3 model with three right-handed Majorana neutrinos and three Higgs doublets, to reduce one parameter in the case when two of the right-handed neutrinos are…
In this work, we explore soft leptogenesis in the NMSSM framework extended by a right-handed neutrino superfield. We calculate the CP asymmetry, $\varepsilon$, and find it to be non-zero at tree-level without using thermal effects for the…
We consider an extension of the Standard Model with three right-handed neutrinos, endowed with a flavour symmetry $G_f$, $G_f=\Delta (3 \, n^2)$ or $G_f=\Delta (6 \, n^2)$, $n \geq 2$, and CP. For large active-sterile mixing, we study the…
In some classes of flavour models based on unified theories with a type I see-saw mechanism, the prediction for the mass of the lightest right-handed neutrino is in conflict with the lower bound from the requirement of successful thermal…
In order to address the baryon asymmetry in the Universe one needs to understand the origin of baryon (B) and lepton (L) number violation. In this article, we discuss the mechanism of baryogenesis via leptogenesis to explain the…
Current experimental data allow the zero value for one neutrino mass, either m_1 = 0 or m_3 = 0. This observation implies that a realistic neutrino mass texture can be established by starting from the limit (a) m_1 = m_2 = 0 and m_3 \neq 0…
By extending the lepton sector of standard model to include one sterile neutrino and two sets of new Higgs doublets and right-handed neutrinos, denoted by $(\eta_1, N_1, N_3)$ and $(\eta_2, N_2, N_4)$, with two $Z_2$ symmetries, the puzzles…
If the baryon asymmetry of the Universe is produced by leptogenesis, CP violation is required in the lepton sector. In the seesaw extension of the Standard Model with three hierarchical right-handed neutrinos, we show that the baryon…