Related papers: Mini-charged tau neutrinos?
In gauge theories like the standard model, the electric charges of the fermions can be heavily constrained from the classical structure of the theory and from the cancellation of anomalies. We argue that the anomaly conditions are not quite…
If the tau neutrino is as heavy as 10 MeV which may have certain astrophysical implications, the neutrino mass pattern is studied so as to accommodate the new oscillation observations. It predicts that the electron neutrino has Marjorana…
The influence of a massive Majorana tau-neutrino on primordial nucleosynthesis is rigorously calculated. The system of three integro-differential kinetic equations is solved numerically for the tau-neutrino mass in the interval from 0 to 20…
In various extensions of the Standard Model of particle physics, and intriguingly even in the three-generation Standard Model without neutrino masses, neutrinos are allowed to have very tiny electric charges. After a review of the…
In this talk I review the present bounds on the tau neutrino, concentrating on the possibility of bringing the mass bound below an MeV.
We point out the following astrophysical consequences of a tau neutrino with mass in the MeV range: (i) if it has a small electric charge which will allow it to become a cold dark matter of the universe, then present limits on the 511 KeV…
Terrestrial and ``Heavenly'' experiments severely constrain the mass and lifetime of an MeV tau neutrino. Irrespective of decay mode, for $\tau_\nu \ga 300\sec$ the mass of the tau neutrino must be either approximately $30\MeV$ or less than…
The emission of $\MeV$-mass tau neutrinos from newly formed neutron stars is considered in a simple, but accurate, model based upon the diffusion approximation. The tau-neutrinosphere temperature is found to increase with mass so that…
A limit on the mass of the tau neutrino is derived from 4.5x10^6 tau pairs produced at a center of mass energy of 10.6 GeV. The measurement technique involves a two-dimensional extended likelihood analysis, including the dependence of the…
The primordial abundance of long-lived heavy Majorana neutrinos is calculated from the full Boltzmann equation. Inclusion of scattering reactions drastically change the predicted abundance of a heavy neutrino species. This loosens the well…
In the minimal Standard Model (MSM) with three generations of quarks and leptons, neutrinos can have tiny charges consistent with electromagnetic gauge invariance. There are three types of non-standard electric charge, given by $Q_{st} +…
Neutrinos are neutral in the Standard Model, but they have tiny charge radii generated by radiative corrections. In theories Beyond the Standard Model, neutrinos can also have magnetic and electric moments and small electric charges…
We show that in the presence of sufficiently strong tau neutrino annihilations into majorons, the primordial nucleosynthesis constraints can not rule out tau neutrino masses in the MeV range.
We consider the influence of non-equilibrium electronic neutrinos (and anti-neutrinos) on the neutron-to-proton ratio. These neutrinos would come from massive $\nu_\tau$ annihilations $\bar \nu_\tau \nu_\tau \rightarrow \bar \nu_e \nu_e$.…
Recent proposals to study the mass of the "electron" neutrino at a sensitivity of 0.3 eV can be used to place limits on the right handed and scalar charged currents at a level which improves on the present experimental limits. Indeed the…
We determine the restrictions imposed by primordial nucleosynthesis upon a heavy tau neutrino, in the presence of nu-tau annihilations into Majorons, as expected in a wide class of particle physics models of neutrino mass. We determine the…
It is supposed that the electron neutrino mass is related to the structures and masses of the $W^\pm$ and $Z^0$ bosons. Using a composite model of fermions (described elsewhere), it is shown that the massless neutrino is not consistent with…
We present the limits on possible time variation of the electric charges of quarks and leptons at the time of primordial nucleosynthesis within a model with dequantized electric charges which allows for the case of charged neutrino and…
A calculation of neutrino decoupling in the early Universe, including full Fermi-Dirac statistics and electron mass dependence in the weak reaction rates, is presented. We find that after decoupling, the electron neutrinos contribute 0.83\%…
Despite direct observations favoring a low mass density, a critical density universe with a neutrino component of dark matter provides the best existing model to explain the observed structure of the universe over more than three orders of…