11 research outputs found
The MSW effect in a fluctuating matter density
We consider the effect on matter-enhanced neutrino flavor transformation of a
randomly fluctuating, delta-correlated matter density. The fluctuations will
produce a distribution of neutrino survival probabilities. We find the mean and
variance of the distribution for the case of solar neutrinos, and discuss the
possibility of placing a limit on solar density fluctuations using neutrino
data.Comment: 20 LaTeX pages plus 24 Postscript figures; submitted to Phys. Rev. D;
also available at http://nucth.physics.wisc.edu/preprints/mad-nt-96-01.tar.g
Neutrino Mixing and Nucleosynthesis in Core-Collapse Supernovae
A simple description of core-collapse supernovae is given. Properties of the
neutrino-driven wind, neutrino fluxes and luminosities, reaction rates, and the
equilibrium electron fraction in supernova environments are discussed. Neutrino
mixing and neutrino interactions that are relevant to core-collapse supernovae
are briefly reviewed. The values of electron fraction under several evolution
scenarios that may impact rapid neutron capture process (r-process)
nucleosynthesis are calculated.Comment: 17 pages, 4 figure
Supernova Neutrino-Nucleus Astrophysics
In this brief review we explore the role of neutrino-nucleus interactions in
core-collapse supernovae and discuss open questions. In addition implications
of neutrino mass and mixings in such environments are summarized.Comment: Revtex 4 figure
Relativistic diffusion of elementary particles with spin
We obtain a generalization of the relativistic diffusion of Schay and Dudley
for particles with spin. The diffusion equation is a classical version of an
equation for the Wigner function of an elementary particle. The elementary
particle is described by a unitary irreducible representation of the Poincare
group realized in the Hilbert space of wave functions in the momentum space.
The arbitrariness of the Wigner rotation appears as a gauge freedom of the
diffusion equation. The spin is described as a connection of a fiber bundle
over the momentum hyperbolic space (the mass-shell). Motion in an
electromagnetic field, transport equations and equilibrium states are
discussed.Comment: 21 pages,minor changes,the version published in Journ.Phys.
Progress in the physics of massive neutrinos
The current status of the physics of massive neutrinos is reviewed with a
forward-looking emphasis. The article begins with the general phenomenology of
neutrino oscillations in vacuum and matter and documents the experimental
evidence for oscillations of solar, reactor, atmospheric and accelerator
neutrinos. Both active and sterile oscillation possibilities are considered.
The impact of cosmology (BBN, CMB, leptogenesis) and astrophysics (supernovae,
highest energy cosmic rays) on neutrino observables and vice versa, is
evaluated. The predictions of grand unified, radiative and other models of
neutrino mass are discussed. Ways of determining the unknown parameters of
three-neutrino oscillations are assessed, taking into account eight-fold
degeneracies in parameters that yield the same oscillation probabilities, as
well as ways to determine the absolute neutrino mass scale (from beta-decay,
neutrinoless double-beta decay, large scale structure and Z-bursts). Critical
unknowns at present are the amplitude of \nu_\mu to \nu_e oscillations and the
hierarchy of the neutrino mass spectrum; the detection of CP violation in the
neutrino sector depends on these and on an unknown phase. The estimated
neutrino parameter sensitivities at future facilities (reactors, superbeams,
neutrino factories) are given. The overall agenda of a future neutrino physics
program to construct a bottom-up understanding of the lepton sector is
presented.Comment: 111 pages, 35 figures. Update
Neutrino Oscillations in Noisy Media
We develop the Redfield equation for delta-correlated gaussian noise and apply it to the case of two neutrino flavor or spin precession in the presence of a noisy matter density or magnetic field, respectively. The criteria under which physical fluctuations can be well approximated by the delta-correlated gaussian noise for the above cases are examined. Current limits on the possible neutrino magnetic moment and solar magnetic field suggest that a reasonably noisy solar magnetic field would not appreciably affect the solar electron neutrino flux. However, if the solar electron density has fluctuations of a few percent of the local density and a small enough correlation length, the MSW effect is suppressed for a range of parameters. 1 INTRODUCTION Neutrino oscillations in the presence of matter and magnetic fields have been an area of intense study for approximately the last ten years. In the Mikheyev - Smirnov - Wolfenstein (MSW) effect, electron neutrinos on their journey from the co..
The MSW effect in a fluctuating matter density
We consider the effect on matter-enhanced neutrino flavor transformation of a randomly fluctuating, delta-correlated matter density. The fluctuations will produce a distribution of neutrino survival probabilities. We find the mean and variance of the distribution for the case of solar neutrinos, and discuss the possibility of placing a limit on solar density fluctuations using neutrino data. 1 Introduction Matter-enhanced neutrino oscillations, especially in connection to the solar neutrino problem [1], have been extensively studied in the recent years. More E-mail address: [email protected] y E-mail address: [email protected] z Present address: Systems for Market Research, Pittsburgh, PA 15229; E-mail address: [email protected] recently some interest has developed in the problem of neutrino flavor transformations via the Mikheyev-Smirnov-Wolfenstein (MSW) effect in a randomly fluctuating matter density. A general approach to neutrino oscillations in suc..
Effects of Random Density Fluctuations on Matter-Enhanced Neutrino Flavor Transitions in Supernovae and Implications for Supernova Dynamics and Nucleosynthesis
We calculate the effects of random density fluctuations on twoneutrino flavor transformations ( ø(¯) * ) e ) in the post-core-bounce supernova environment. In particular, we follow numerically the flavor evolution of neutrino states propagating through a stochastic field of density fluctuations. We examine the approach to neutrino flavor depolarization, and study the effects of this phenomenon in both the early shock reheating epoch and the later r-process nucleosynthesis epoch. Our results suggest that significant fluctuation-induced neutrino flavor depolarization effects occur in these environments only when the zero-order (without density fluctautions) evolution of the neutrino states includes adiabatic propagation through resonances (mass level crossings). In the shock reheating epoch, depolarization Permanent address: Department of Physics, University of California, San Diego, La Jolla, CA 92093-0319. y Permanent address: Department of Physics, University of Wisconsin, Madi..