Related papers: Nature Itself in a Mirror Space-Time
Leptogenesis typically requires the introduction of heavy particles whose out-of-equilibrium decays are essential for generating a matter-antimatter asymmetry, according to one of Sakharov's conditions. We demonstrate that in Dirac…
We analyze a scenario where the right-handed neutrinos make part of a strongly coupled conformal field theory and acquire an anomalous dimension \gamma<1 at a large scale \Lambda. Their Yukawa couplings to the Higgs become irrelevant at the…
If dark matter is light, it may be due to a seesaw mechanism just as neutrinos are. It is postulated that both originate from the same type of heavy fermion anchors, either singlets or triplets. In the latter case, a shift of the $W$ mass…
We make a general analysis of neutrino phenomenology for the case neutrino masses are generated by the see-saw mechanism with just two right handed neutrinos. We find general constraints on leptogenesis and lepton flavour violating…
We present a class of left-right symmetric models where Dirac as well as Majorana mass terms of neutrinos can arise at one-loop level in a scotogenic fashion: with dark matter particles going inside the loop. We show the possibility of…
We propose a modified Dirac equation for a massive neutrino moving in the presence of the background matter. The effects of the charged and neutral-current interactions with the matter as well as the matter motion and polarization are…
A right-handed neutrino is a promising candidate for dark matter (DM) which has no interaction with nuclei. Since two right-handed neutrinos explain neutrino oscillation data and baryon number asymmetry through both the seesaw mechanism and…
Comparison of properties of quark and leptons as well as understanding their similarities and differences is one of the milestones on the way to underlying physics. Several observations, if not accidental, can strongly affect the…
Left-right (LR) symmetric theories predict right-handed charged currents whose flavor structure encodes the realization of parity. While the right-handed quark mixing matrix closely tracks its left-handed counterpart, the leptonic sector…
Finding out if neutrinos are Dirac or Majorana particles is known to be extremely difficult. This is generally believed to be due to the smallness of the neutrino mass compared to typical neutrino energies, and to the fact that in the limit…
The discovery of neutrino oscillations provides a solid evidence for nonzero neutrino masses and leptonic mixing. The fact that neutrino masses are so tiny constitutes a puzzling problem in particle physics. From the theoretical viewpoint,…
We propose to relate dark matter stability to the possible Dirac nature of neutrinos. The idea is illustrated in a simple scheme where small Dirac neutrino masses arise from a type--I seesaw mechanism as a result of a $Z_4$ discrete lepton…
We argue that the long-standing issues of neutrino mass and dark matter can be manifestly solved in a dark gauge symmetry $U(1)_D$ that transforms nontrivially only for three right-handed neutrinos $\nu_{1,2,3R}$ -- the counterparts of…
The observed pattern of lepton flavor mixing and CP violation strongly indicates the possible existence of a simple flavor symmetry in the neutrino sector -- the effective Majorana neutrino mass term keeps invariant when the three…
The fundamental issue of the origin of mass for all quarks and leptons (including Majorana neutrinos) is linked to dark matter, odd under an exactly conserved Z(2) symmetry which may or may not be derivable from an U(1) gauge symmetry. The…
Flipping a symmetry often leads to a more fundamental symmetry and new physics insight. Applying this principle to the standard model electroweak symmetry, we obtain a novel gauge symmetry, which defines dark charge besides electric charge,…
We propose a model for neutrino masses that simultaneously results in a new dark matter candidate, the right-handed neutrino. We derive the dark matter abundance in this model, show how the hierarchy of neutrino masses is obtained, and…
Symplectic flavour symmetry group Sp(n/2) (n is even) of n Majorana states does not allow for invariant Majorana masses. Only specific mass matrices with diagonal and nondiagonal elements are possible here. As a result of the spontaneous…
We explore a simple solution to the cosmological challenges of the original Mirror Twin Higgs (MTH) model that leads to interesting implications for experiment. We consider theories in which both the standard model and mirror neutrinos…
We consider the matter effects on neutrinos moving in background on the basis of the corresponding quantum wave equations. Both Dirac and Majorana neutrino cases are discussed. The effects for Dirac neutrino reflection and trapping as well…