相关论文: Precise Nucleosynthesis Limits on Neutrino Masses

A limit on the mass of the tau neutrino is derived from 4.5 million tau pairs produced in an integrated luminosity of 5.0 fb^{-1} of electron-positron annihilation to tau pairs at center of mass energies near 10.6 GeV. The measurement…

We analyze the implications of neutrino masses for the magnitude of neutrino magnetic moments. By considering electroweak radiative corrections to the neutrino mass, we derive model-independent naturalness upper bounds on neutrino magnetic…

Massive neutrinos are guaranteed to have nonzero electromagnetic moments and, since there are at least three neutrino species, these dipole moments define a matrix. Here, we estimate the current upper bounds on all independent neutrino…

We analyse the effects of Dirac and Majorana neutrinos on leptonic decays of muon and tau leptons using the most general four-lepton effective interaction Hamiltonian of dimension six. We calculate the specific energy and angular…

Are neutrinos with definite masses Majorana or Dirac particles? This is one of the most fundamental problem of the modern neutrino physics. The solution of this problem could be crucial for understanding of the origin of small neutrino…

We revisit the recent limits from LHCb on a Majorana neutrino N in the mass range 250 - 5000 MeV. These limits are among the best currently available, and they will be improved soon by the addition of data from Run 2 of the LHC. LHCb…

Normal muon decay, $\mu^{+} \to e^{+}\nu_{e}\bar{\nu_{\mu}}$, is studied as a tool to discriminate between the Dirac and Majorana types of neutrinos and to survey the structure of the weak interaction. It is assumed that massive neutrinos…

From 21 independent Baryon Acoustic Oscillation (BAO) measurements we obtain the following sum of masses of active Dirac or Majorana neutrinos: $\sum m_\nu = 0.711 - 0.335 \cdot \delta h + 0.050 \cdot \delta b \pm 0.063 \textrm{ eV,}$ where…

The case for small neutrino mass differences from atmospheric and solar neutrino oscillation experiments has become compelling, but leaves the overall neutrino mass scale m_nu undetermined. The most restrictive limit of m_nu < 0.8 eV arises…

The best upper bounds on the masses of stable and unstable light neutrinos derive from the upper bound on the total mass density, as inferred from the lower limit $t_0> 13$ Gyr on the dynamical age of the Universe: If the Universe is…

Neutrino masses are yet unknown. We discuss the present state of effective electron anti-neutrino mass from $\beta$ decay experiments; effective Majorana neutrino mass from neutrinoless double-beta decay experiments; neutrino mass squared…

The capture rates of non-relativistic neutrinos on beta decaying nuclei depends on whether their mass is Dirac or Majorana. It is known that for relic neutrinos from the big-bang, and within minimal assumptions, the rate is a factor two…

The lepton-number violating process e p \to nu_e l l' X mediated by Majorana neutrinos is studied for the HERA collider for (l l') = (e tau), (mu tau), (mu mu) and (tau tau). Only the muonic decay of the tau is considered. The direct limit…

Two general models with hierarchical and almost degenerate neutrino masses, which are able to explain the solar and atmospheric anomalies are investigated. We show how neutrinoless double beta decay experiments discern Dirac and Majorana…

New nucleosynthesis bounds on the oscillation parameters of active neutrinos mixed with a sterile one are derived for the non-resonant case. The controversy in the literature whether to use the annihilation rate or the total reaction rate…

We calculate the coherent bremsstrahlung process $\nu+{\cal N} \to {\cal N}+\nu+\gamma$ off a nucleus ${\cal N}$ with the aim of revealing the neutrino mass via the photon endpoint spectrum. Unfortunately, the large required power of a…

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 article I review the constraints on neutrino mass and mixing coming from type-II supernovae. The bounds obtained on these parameters from shock reheating, r-process nucleosynthesis and from SN1987A are discussed. Given the current…

After a quick review of astrophysically relevant limits, I present a summary of MeV scale tau neutrino mass limits derived from accelerator based experiments. I argue that the current published limits appear to be too consistent, and that…

Thermal dark matter that couples more strongly to electrons and photons than to neutrinos will heat the electron-photon plasma relative to the neutrino background if it becomes nonrelativistic after the neutrinos decouple from the thermal…