Sterile neutrinos and Big Bang Nucleosynthesis in the 3 + 1 scheme

2014 ◽  
Vol 23 (03) ◽  
pp. 1450014 ◽  
Author(s):  
Mercedes Elisa Mosquera ◽  
Osvaldo Civitarese
Keyword(s):  
Distribution Function ◽  
Sterile Neutrino ◽  
Big Bang ◽  
Light Nuclei ◽  
Wilkinson Microwave Anisotropy Probe ◽  
Normalization Constant ◽  
Big Bang Nucleosynthesis ◽  
Sterile Neutrinos ◽  
Mixing Angle ◽  
Free Parameters

We study the effects of adding a sterile neutrino to three active neutrinos (3 + 1 scheme) in the calculation of primordial abundances. Taking the normalization constant (a) of the occupation factor of the sterile neutrino and the active-sterile mixing angle (ϕ) as free parameters, we calculate the neutrino distribution function and primordial abundances of light nuclei. We set constrains on these parameters by using the available data on the abundances of D, 4 He and 7 Li . Results are consistent with small values of a and ϕ. The extracted value of the baryon-to-photon ratio (ηB), which is constrained by the Wilkinson Microwave Anisotropy Probe (WMAP) value [Formula: see text], and Planck observations, depends strongly on the inclusion of the lithium data in the fit.

scholarly journals A model for mixed warm and hot right-handed neutrino dark matter

2021 ◽  
Vol 2021 (10) ◽  
Author(s):  
Maíra Dutra ◽  
Vinícius Oliveira ◽  
C. A de S. Pires ◽  
Farinaldo S. Queiroz
Keyword(s):  
Dark Matter ◽  
Degrees Of Freedom ◽  
Sterile Neutrino ◽  
Big Bang ◽  
Matter Density ◽  
The Other ◽  
Big Bang Nucleosynthesis ◽  
Sterile Neutrinos ◽  
Dark Matter Density ◽  
Model Features

Abstract We discuss a model where a mixed warm and hot keV neutrino dark matter rises naturally. We arrange active and sterile neutrinos in the same SU(3)L multiplet, with the lightest sterile neutrino being dark matter. The other two heavy sterile neutrinos, through their out-of-equilibrium decay, contribute both to the dilution of dark matter density and its population, after freeze-out. We show that this model features all ingredients to overcome the overproduction of keV neutrino dark matter, and explore the phenomenological implications for Big Bang Nucleosynthesis and the number of relativistic degrees of freedom.

EFFECT OF NEGATIVELY-CHARGED MASSIVE PARTICLES ON BIG-BANG NUCLEOSYNTHESIS AND A SOLUTION TO THE LITHIUM PROBLEMS

2008 ◽  
Vol 23 (17n20) ◽  
pp. 1668-1674
Author(s):  
MOTOHIKO KUSAKABE ◽  
TOSHITAKA KAJINO ◽  
RICHARD N. BOYD ◽  
TAKASHI YOSHIDA ◽  
GRANT J. MATHEWS
Keyword(s):  
Charged Particle ◽  
Nuclear Reactions ◽  
Charged Particles ◽  
Big Bang ◽  
Light Nuclei ◽  
Big Bang Nucleosynthesis ◽  
Spectroscopic Observations ◽  
Halo Stars ◽  
Wmap Data ◽  
Ionization Processes

Spectroscopic observations of metal poor halo stars give an indication of a possible primordial plateau of 6 Li abundance as a function of metallicity similar to that for 7 Li . The inferred abundance of 6 Li is ~1000 times larger than that predicted by standard big bang nucleosynthesis (BBN) for the baryon-to-photon ratio inferred from the WMAP data, and that of 7 Li is about 3 times smaller than the prediction. We study a possible solution to both the problems of underproduction of 6 Li and overproduction of 7 Li in BBN. This solution involves a hypothetical massive, negatively-charged particle that would bind to the light nuclei produced in BBN. The particle gets bound to the existing nuclei after the usual BBN, and a second epoch of nucleosynthesis can occur among nuclei bound to the particles. We numerically carry out a fully dynamical BBN calculation, simultaneously solving the recombination and ionization processes of negatively-charged particles by normal and particle-bound nuclei as well as many possible nuclear reactions among them. It is confirmed that BBN in the presence of these hypothetical particles can solve the two Li abundance problems simultaneously.

scholarly journals A Sterile Neutrino Scenario Constrained By Experiments and Cosmology

1997 ◽  
Vol 12 (21) ◽  
pp. 3669-3694 ◽  
Author(s):  
Nobuchika Okada ◽  
Osamu Yasuda
Keyword(s):  
Total Mass ◽  
Sterile Neutrino ◽  
Neutrinoless Double Beta Decay ◽  
Big Bang ◽  
Double Beta Decay ◽  
Big Bang Nucleosynthesis ◽  
Negative Results ◽  
Equivalent Number ◽  
Mixing Matrix ◽  
Model Independent

We analyze a scheme in which three active neutrinos and one sterile neutrino account for the solar, the atmospheric and the LSND neutrino anomalies in a model-independent way. It is shown that if the equivalent number, Nν, of the light neutrino species is less than 4, then the constraints from these anomalies, accelerator and reactor experiments and big bang nucleosynthesis force a general 4 × 4 mixing matrix to be effectively split into two 2 × 2 matrices. If these neutrinos are of the Majorana type, then negative results of neutrinoless double beta decay experiments imply that the total mass of neutrinos is not sufficient to account for all the hot dark matter components.

scholarly journals NEUTRINO SPECTRUM DISTORTION DUE TO OSCILLATIONS AND ITS BBN EFFECT

2004 ◽  
Vol 13 (05) ◽  
pp. 831-841 ◽  
Author(s):  
DANIELA KIRILOVA
Keyword(s):  
Sterile Neutrino ◽  
Big Bang ◽  
Neutrino Energy ◽  
Electron Neutrino ◽  
Initial Population ◽  
Neutrino Mixing ◽  
Big Bang Nucleosynthesis ◽  
Cosmological Constraints ◽  
Neutrino Spectrum ◽  
Primordial Abundance

We study the distortion of electron neutrino energy spectrum due to oscillations with the sterile neutrino νe↔νs, for different initial populations of the sterile state δNs at the onset of oscillations. The influence of this spectrum distortion on Big Bang Nucleosynthesis is analyzed. Only the case of an initially empty sterile state was studied in previous publications. The primordial abundance of 4He is calculated for all possible δNs:0≤δNs≤1 in the model of oscillations, effective after electron neutrino decoupling, for which the spectrum distortion effects on the neutron–proton transitions are the strongest. It is found that the spectrum distortion effect may be dominant, not only in the case of small δNs, but also in the case of large initial population of νs. For example, in the resonant case it may play a considerable role even for very large δNs~0.8. Cosmological constraints on neutrino mixing for small δNs are discussed.

LARGE MIXING ANGLE STERILE NEUTRINOS AND PULSAR VELOCITIES

2009 ◽  
Vol 24 (31) ◽  
pp. 2507-2516 ◽  
Author(s):  
LEONARD S. KISSLINGER ◽  
ERNEST M. HENLEY ◽  
MIKKEL B. JOHNSON
Keyword(s):  
Magnetic Field ◽  
Sterile Neutrino ◽  
Effective Volume ◽  
Sterile Neutrinos ◽  
Mixing Angle ◽  
Lowest Landau Level ◽  
Neutrino Emissivity ◽  
Global Fit ◽  
Temperature Equilibrium ◽  
Protoneutron Star

We investigate the momentum given to a protoneutron star, the pulsar kick, during the first ten seconds after temperature equilibrium is reached. Using a model with two sterile neutrinos obtained by fits to the MiniBooNE and LSND experiments, which is consistent with a new global fit, there is a large mixing angle, and the effective volume for emission is calculated. Using formulations with neutrinos created by URCA processes in a strong magnetic field, so the lowest Landau level has a sizable probability, we find that with known parameters, the asymmetric sterile neutrino emissivity might account for large pulsar kicks.

scholarly journals THE STATUS OF NEUTRINO MASS

1998 ◽  
Vol 13 (25) ◽  
pp. 4409-4423 ◽  
Author(s):  
DAVID O. CALDWELL
Keyword(s):  
Dark Matter ◽  
Neutrino Mass ◽  
Heavy Element ◽  
Sterile Neutrino ◽  
Big Bang ◽  
Atmospheric Neutrinos ◽  
Big Bang Nucleosynthesis ◽  
Robust Solution ◽  
The Status ◽  
Mass Pattern

New experimental results, if correct, require at least one light sterile neutrino, in addition to the three active ones, to accommodate the mass differences required to explain the solar νe deficit, the anomalous μ/e ratio produced by atmospheric neutrinos, and either the candidate events for νμ→ νe (or [Formula: see text]) from the LSND experiment, or the possible need for a hot component of dark matter. This neutrino mass pattern can not only accommodate all these four requirements, but also provide a robust solution to a problem presently making heavy-element synthesis by supernovae impossible and resolve a possible discrepancy between big bang nucleosynthesis theory and observations.

BBN AND NEUTRINO OSCILLATIONS IN THE EARLY UNIVERSE: A BRIEF REVIEW

2005 ◽  
Vol 20 (11) ◽  
pp. 2431-2435
Author(s):  
F. L. VILLANTE
Keyword(s):  
Early Universe ◽  
Neutrino Oscillations ◽  
Sterile Neutrino ◽  
Big Bang ◽  
Big Bang Nucleosynthesis

We briefly review the physics of Big Bang Nucleosynthesis (BBN). We present, moreover, some recent results on active-sterile neutrino oscillations in the early universe and on their effects on BBN.

scholarly journals Effects of active–sterile neutrino mixing during primordial nucleosynthesis

2014 ◽  
Vol 23 (12) ◽  
pp. 1450080 ◽  
Author(s):  
Osvaldo Civitarese ◽  
Mercedes Elisa Mosquera ◽  
María Manuela Sáez
Keyword(s):  
Neutrino Mass ◽  
Sterile Neutrino ◽  
Distribution Functions ◽  
Light Nuclei ◽  
Neutrino Mixing ◽  
Mixing Angles ◽  
A Value ◽  
Active Neutrino ◽  
Observable Data ◽  
Free Parameters

In the present work, we discuss the effects of the inclusion of sterile–active neutrino oscillations during the production of primordial light-nuclei. We assume that the sterile neutrino mass-eigenstate might oscillate with the two lightest active neutrino mass-eigenstates, with mixing angles ϕ1 and ϕ2. We also allow a constant renormalization (represented by a parameter (ζ)) of the sterile neutrino occupation factor. Taking ζ and the mixing angles as free parameters, we have computed distribution functions of active and sterile neutrinos and primordial abundances. Using observable data we set constrains in the free parameters of the model. It is found that the data on primordial abundances are consistent with small mixing angles and with a value of ζ smaller than 0.65 at 3σ level.

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