Related papers: Comment on ``Can gravity distinguish between Dirac…
These lectures describe some aspects of the physics of massive neutrinos. After a brief introduction of neutrinos in the Standard Model, I discuss possible patterns for their masses. In particular, I show how the presence of a large…
These are lectures given at the CERN-JINR school on high energy physics. The possibilities of the mixing of massive Dirac and Majorana neutrinos are discussed. The theory of neutrino oscillations in vacuum is presented. The trasitions…
In spite of the general belief that neutrinos are Majorana particles, their character should be revealed experimentally. We begin by discussing why it is so difficult in terrestrial experiments. If neutrinos are Majorana particles, the…
Cross sections involving massive Dirac or Majorana neutrinos usually differ only by terms which are suppressed by the smallness of the neutrino mass. The process $e^+e^-\to\nu\nu$, however, is an example in which the two differential cross…
It is shown that we cannot put Majorana neutrinos in the standard Dirac theory without violation of the gauge invariance. Experiments on $\nu_l \to l (l = e, \mu, \tau)$ transitions do not confirm this supposition. It means that on neutrino…
Due to the standard electroweak model we have become accustomed to think about a neutrino $\nu$ and its antineutrino $\bar \nu$ as distinct particles. However, it has long been recognized that the apparent distinction between them may be…
Large colliders are not sensitive to light neutrino masses and character, but they can produce new heavy neutrinos, allowing also for the determination of their Dirac or Majorana nature. We review the discovery limits at the next generation…
In this paper the interaction of high energy neutrinos with weak gravitational fields is briefly explored. The form of the graviton-neutrino vertex is motivated from Lorentz and gauge invariance and the non-relativistic interpretations of…
The nature of a neutrino, whether it is a Dirac type or Majorana type, may be comprehensively probed using their quantum statistical properties. If the neutrino is a Majorana fermion, then by definition it is identical and indistinguishable…
There are now strong hints suggesting that neutrinos do have a mass after all. If they do have a mass, it would have to be tiny. Why is it so? Is it Dirac or Majorana? Can one build a model in which a teeny, tiny Dirac neutrino mass arises…
The history of research associated with the fundamental problem of the nature of massive neutrinos, which can be Dirac particles or Majorana fermions, and the related processes of neutrinoless double beta decay, $(A,Z)\rightarrow (A,Z+2) +…
A novel method to differentiate the effects of Dirac and Majorana (D-M) neutrinos in four-body decays has been discussed in arXiv:2106.11785. There, it is concluded that the back-to-back kinematic scenario seems to avoid the constraint…
Expository notes on Clifford algebras and spinors with a detailed discussion of Majorana, Weyl, and Dirac spinors. The paper is meant as a review of background material, needed, in particular, in now fashionable theoretical speculations on…
This paper reviews the current status and future outlook of neutrinoless double beta decay searches, which try to provide an answer to the fundamental question of whether neutrinos are Dirac or Majorana particles.
The topics discussed in this lecture include: general properties of neutrinos in the SM, the theory of neutrino masses and mixings (Dirac and Majorana), neutrino oscillations both in vacuum and in matter, an overview of the experimental…
This is an elementary account of neutrinos as Majarona particles and the search for neutrinoless double beta decays. It also includes some more ideas about neutrinos.
In this paper we investigate how well the nature of heavy neutral leptons can be determined at a future lepton collider, after its potential discovery. Considered in a simplified model are prompt decays of the neutrino in the mass range…
It is shown that various versions of the neutrino mixing hypothesis are in a contradiction with generally accepted facts and principles.There is also presented the possible alternative formulation of the neutrino oscillation theory and it…
We introduce the Majorana spinors in the momentum representation. They obey the Dirac-like equation with eight components, which has been first introduced by Markov. Thus, the Fock space for corresponding quantum fields is doubled (as shown…
Massive neutrinos can have helicity $s_{\parallel}\neq -1$. Neutrino helicity changes when the neutrino interacts with an external magnetic field and it is possible that the left-handed neutrinos born inside the Sun or a supernova could…