Related papers: B-L Cosmic strings and Baryogenesis
Assuming only a hierarchical structure of the heavy Majorana neutrino masses and of the neutrino Dirac mass matrix m_D of the see-saw mechanism, we find that in order to produce the observed baryon asymmetry of the Universe via…
Cosmic strings, theoretical one-dimensional topological defects from the early universe, provide a valuable opportunity for exploring dark matter (DM) production and gravitational wave (GW) emission. Our study investigates the production of…
Finding a plausible origin for right-handed neutrino Majorana masses in semirealistic compactifications of string theory remains one of the most difficult problems in string phenomenology. We argue that right-handed neutrino Majorana masses…
We study the scenario of electroweak baryogenesis mediated by nonsuperconducting cosmic strings. This idea relies upon electroweak symmetry being restored in a region around the core of the topological defect so that, within this region,…
We investigate a general $U(1)_X$ scenario where we introduce three generations of Standard Model (SM) singlet Right Handed Neutrinos (RHNs) to generate the light neutrino mass through the seesaw mechanism after the breaking of $U(1)_X$ and…
We consider a minimal non-supersymmetric $SO(10)$ Grand Unified Theory (GUT) model that can reproduce the observed fermionic masses and mixing parameters of the Standard Model. We calculate the scales of spontaneous symmetry breaking from…
We investigate a scheme for making leptogenesis by means of the CP violating decays of the seesaw Majorana neutrinos proposed by Fukugita and Yanagida. However, in order to avoid the wash-out of the produced lepton number we propose the…
In a recent paper, the NANOGrav collaboration studied new physics explanations of the observed pulsar timing residuals consistent with a stochastic gravitational wave background (SGWB), including cosmic strings in the Nambu-Goto (NG)…
The extension of the Standard Model by heavy right-handed neutrinos can simultaneously explain the observed neutrino masses via the seesaw mechanism and the baryon asymmetry of the Universe via leptogenesis. If the mass of the heavy…
The B-L extension of the Standard Model requires the existence of right-handed neutrinos and naturally realizes the seesaw mechanism of neutrino mass generation. We study the possibility of explaining the dark matter in this model with an…
We compute the effective coupling of the Majoron to W bosons at $\cO(\hbar)$ by evaluating the matrix element of the (B-L) current between the vacuum and a $W^+W^-$ state. The (B-L) anomaly vanishes, but the amplitude does not vanish as a…
We build a supersymmetric version with $SU(3)_{C}\otimes SU(2)_{L}\otimes U(1)_{Y^{\prime}}\otimes U(1)_{(B-L)}$ gauge symmetry, where $Y^{\prime}$ is a new charge and ($B$) and ($L$) are the usual baryonic and leptonic numbers,…
We reexamine sterile neutrino dark matter in gauged $U(1)_{B-L}$ model. Improvements have been made by tracing and careful evaluation of the evolution of the number densities of sterile neutrinos $N$ and extra neutral gauge bosons $Z'$. As…
In this work we demonstrate that what was previously considered as different mechanisms of baryon asymmetry generation involving two right-handed Majorana neutrinos with masses far below the GUT scale -- leptogenesis via neutrino…
Majoron models provide neutrino masses via the spontaneous breaking of a global $U(1)$ symmetry. However, it may be argued that all global symmetries will be explicitly violated by gravitational effects. We show that it is possible to…
Cosmic strings can arise in hidden sector models with a spontaneously broken Abelian symmetry group. We have studied the couplings of the Standard Model fields to these so-called dark strings in the companion paper. Here we survey the…
The minimal flipped $SU(5)$ unification with the right-handed neutrino Majorana mass scale generated as a two-loop effect is arguably one of the most constrained models of perturbative baryon and lepton number violation currently on the…
We investigate the effect of B+L - violating anomalous generation of massive right-handed neutrinos on their decoupling, when the right-handed neutrino mass is considerably greater than the right-handed gauge boson masses. Considering…
We perform a detailed study of the importance of loop corrections when deriving bounds on heavy-active neutrino mixing in the context of general Seesaw mechanisms with extra heavy right-handed neutrinos. We find that, for low-scale Seesaws…
Cosmological baryon asymmetry B is studied in supersymmetric standard models, assuming the electroweak reprocessing of B and L. Only when the soft supersymmetry breaking is taken into account, B is proportional to the primordial B-L in the…