相关论文: Constraints on Massive Tau Neutrinos and their Cos…
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…
We consider the scenario of large scale structure formation with tau neutrino with mass in the MeV range and lifetime of order of years which decays into a massive majoron with KeV mass. The latter are the present-day cold dark matter…
The tau neutrino with a mass of about 10 MeV can be the ``late decaying particle'' in the cold dark matter scenario for the formation of structure in the Universe. We show how this may be realized specifically in the recently proposed…
The cold dark matter (CDM) scenario for structure formation in the Universe is very attractive and has many successes; however, when its spectrum of density perturbations is normalized to the COBE anisotropy measurement the level of…
In this paper we reconsider recently derived bounds on $MeV$ tau neutrinos, taking into account previously unaccounted for effects. We find that, assuming that the neutrino life-time is longer than $O(100~sec)$, the constraint $N_{eff}<3.6$…
The amount of decaying dark matter, accumulated in the central regions in neutron stars together with the energy deposition rate from decays, may set a limit on the neutron star survival rate against transitions to more compact objects…
We study the growth of density perturbations in a universe with unstable dark matter particles. The mass (m_\nu) range 30 eV < m_\nu < 10 keV with lifetimes ($t_d$) in the range 10^7 sec < t_d < 10^16 sec are considered. We calculate the…
We revisit the constraints implied by SN 1987 A observations on the decay rate of a multi-MeV $\nu_\tau$ decaying into the visible channel $\nu_\tau \rightarrow e^+ e^- \nu_e$, if its lifetime is more than 10 {\it sec.}. We discuss its…
The magnetic moment of tau neutrinos in the MeV mass range may be large enough to modify the cosmological freeze-out calculation and determine the tau-neutrino relic density. In this paper we revisit such a possibility. We calculate the…
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…
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…
We show that there is no one-loop enhancement of the rate for a light neutrino to decay into a lighter neutrino plus a majoron, contrary to a recent claim. Thus the light neutrinos must satisfy the cosmological bound of having masses less…
Comparing Big Bang Nucleosynthesis predictions with the light element abundances inferred from observational data, we can obtain the strong constraints on some neutrino properties, e.g. number of neutrino species, mass, lifetime. Recently…
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 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…
We present a model where sterile neutrinos with rest masses in the range ~ keV to ~ MeV can be the dark matter and be consistent with all laboratory, cosmological, large-scale structure, as well as x-ray constraints. These sterile neutrinos…
Theoretically, the electric charge of the tau neutrino may be non-zero. The experimental bound on the electric charge of the tau neutrino is many orders of magnitude weaker than that for any other known neutrino. If the tau neutrino does…
We review the recent proposal by Lattanzi & Valle of the majoron as a suitable warm dark matter candidate. The majoron is the Goldstone boson associated to the spontaneous breaking of ungauged lepton number, one of the mechanisms proposed…
We point out that, in the left-right symmetric model of weak interaction, if $\nu_\tau$ mass is in the keV to MeV range, there is a strong correlation between rare decays such as $\tau \rightarrow 3 \mu, \tau \rightarrow 3 e$ and the…