Related papers: Leptogenesis with four gauge singlets
We study lepto-axiogenesis in theories where the right-handed neutrino is light enough that its dynamics affect the determination of the baryon asymmetry. When compared with theories of high-scale lepto-axiogenesis where the Majorana…
Seven types of leptogenesis models which can lead to a successful explanation of baryogenesis are presented. Emphasis is put on the conditions which need to be fulfilled by the neutrino masses as well as by the heavy state masses. The model…
Models where the baryon (B) and lepton (L) numbers are local gauge symmetries that are spontaneously broken at a low scale are revisited. We find new extensions of the Standard Model which predict the existence of fermions that carry both…
We study the supersymmetric leptogenesis via $LH_{u}$ flat direction with a gauged $U(1)_{B-L}$ symmetry. We find that the resultant baryon asymmetry is enhanced compared with the case without a gauged $U(1)_{B-L}$ symmetry. The baryon…
The Standard Model is extended by a SU(2)L singlet of vector leptoquarks. An additional SU(4) gauge symmetry between right-handed up quarks and right-handed leptons is introduced to render the model renormalizable. The arrangement is made…
We construct a left-right symmetric (LRS) model in five dimensions which accounts naturally for the lepton flavor parameters. The fifth dimension is described by an orbifold, S_1/Z_2 times Z'_2, with a typical size of order TeV^{-1}. The…
We have studied the scenario of baryogenesis via leptogenesis in an $A_4$ flavor symmetric framework considering type I seesaw as the origin of neutrino mass. Because of the presence of the fifth generation right handed neutrino the model…
We explore a realistic supersymmetric SU(2)_L \times SU(2)_R \times U(1)_B-L model spontaneously broken at around 10^12 GeV. The presence of D and F-flat directions gives rise to TeV mass doubly charged particles which can be found at the…
In this paper we consider generation of naturally small neutrino masses from a dimension-7 operator. Such a term can arise in presence of a scalar quadruplet and a pair of vector-like fermion triplets and enables one to obtain small…
We propose a new mechanism of leptogenesis in which the asymmetries in lepton numbers are produced through the CP-violating oscillations of ``sterile'' (electroweak singlet) neutrinos. The asymmetry is communicated from singlet neutrinos to…
Leptogenesis provides an elegant mechanism to explain the observed baryon asymmetry of the Universe (BAU), yet its experimental verification remains challenging due to requirements of either extremely heavy right-handed neutrinos or…
If the masses of at least two generations of right-handed neutrinos (RHNs) are near-degenerate, the scale of leptogenesis can be as low as $\sim$ 100 GeV. In this work, we study probing such resonant leptogenesis in the $B-L$ model at the…
In the supersymmetric triplet (type-II) seesaw model, in which a single SU(2)_L-triplet couples to leptons, the high-energy neutrino flavour structure can be directly determined from the low-energy neutrino data. We show that even with such…
Strictly adhering to the standard supersymmetric seesaw mechanism, we present a neutrino mass model which allows successful standard thermal leptogenesis compatible with gravitino cosmology. At least some of the neutrino Yukawa couplings…
We study leptogenesis in two seesaw models where maximal atmospheric neutrino mixing and $U_{e3} = 0$ result from symmetries. Salient features of those models are the existence of three Higgs doublets and a twofold degeneracy of the…
We revisit our previous model proposed in Ref. \cite{Okada:2013iba}, in which lepton masses except the tauon mass are generated at the one-loop level in a TeV scale physics. Although in the previous work, rather large Yukawa couplings…
In this paper we discuss a minor modification of a previous SU(5) x A5 flavour model which exhibits at leading order golden ratio mixing and sum rules for the heavy and the light neutrino masses. Although this model could predict all mixing…
We present here a novel and testable mechanism for leptogenesis, which is characterized by a purely thermal generation of lepton asymmetry via scalar decay. Guided by the thermal mass matrix diagonalization in the finite-temperature regime,…
We construct a supersymmetric version of the triplet Higgs model for neutrino masses, which can generate a baryon asymmetry of the Universe through lepton-number violation and is consistent with the gravitino constraints.
It is shown that the type III seesaw mechanism proposed recently can have certain advantages over the conventional (or type I) seesaw mechanism for leptogenesis. In particular a resonant enhancement of leptogenesis via heavy quasi-Dirac…