142,330 research outputs found
Collective Neutrino Oscillations
We review the rich phenomena associated with neutrino flavor transformation
in the presence of neutrino self-coupling. Our exposition centers on three
collective neutrino oscillation scenarios: a simple bipolar neutrino system
that initially consists of mono-energetic electron neutrinos and antineutrinos;
a homogeneous and isotropic neutrino gas with multiple neutrino/antineutrino
species and continuous energy spectra; and a generic neutrino gas in an
anisotropic environment. We use each of these scenarios to illustrate key
facets of collective neutrino oscillations. We discuss the implications of
collective neutrino flavor oscillations for core collapse supernova physics and
for the prospects of obtaining fundamental neutrino properties, e.g., the
neutrino mass hierarchy and from a future observed supernova
neutrino signal.Comment: Submitted to Annual Review of Nuclear and Particle Scienc
Physics of neutrino flavor transformation through matter-neutrino resonances
In astrophysical environments such as core-collapse supernovae and neutron
star-neutron star or neutron star-black hole mergers where dense neutrino media
are present, matter-neutrino resonances (MNRs) can occur when the neutrino
propagation potentials due to neutrino-electron and neutrino-neutrino forward
scattering nearly cancel each other. We show that neutrino flavor
transformation through MNRs can be explained by multiple adiabatic solutions
similar to the Mikheyev-Smirnov-Wolfenstein mechanism. We find that for the
normal neutrino mass hierarchy, neutrino flavor evolution through MNRs can be
sensitive to the shape of neutrino spectra and the adiabaticity of the system,
but such sensitivity is absent for the inverted hierarchy.Comment: 7 pages, 4 figure
Present Status of Neutrino Mixing
A short review of the status of neutrino mixing and neutrino oscillations is
given. The basics of neutrino mixing and oscillations is discussed. The latest
evidences of neutrino oscillations obtained in the Super-Kamiokande and the SNO
solar neutrino experiments and in the Super-Kamiokande atmospheric neutrino
experiment are considered. The results of solar and atmospheric neutrino
experiments are discussed from the point of view of the three-neutrino mixing.Comment: 20 pages, Proceedings of the Advanced Study Institute "Symmetries and
Spin", Praha-Spin-2001, Czech Republic, July 15-28, 200
Progress in neutrino oscillation searches and their implications
Neutrino Oscillation, in which a given flavour of neutrino transforms into
another is a powerful tool for probing small neutrino masses. The intrinsic
neutrino properties involved are neutrino mass squared difference
and the mixing angle in vacuum . In this talk I will summarize the
progress that we have achieved in our search for neutrino oscillation with
special emphasis on the recent results from the Sudbury Neutrino Observatory
(SNO) on the measurement of solar neutrino fluxes. I will outline the current
bounds on the neutrino masses and mixing parameters and discuss the major
physics goals of future neutrino experiments in the context of the present
picture.Comment: Plenary Talk, WHEPP-7, January 2002, published in Pramana, Vol. 60,
261, 200
Neutrino Observatories Can Characterize Cosmic Sources and Neutrino Properties
Neutrino telescopes that measure relative fluxes of ultrahigh-energy
can give information about the location and
characteristics of sources, about neutrino mixing, and can test for neutrino
instability and for departures from CPT invariance in the neutrino sector. We
investigate consequences of neutrino mixing for the neutrino flux arriving at
Earth, and consider how terrestrial measurements can characterize distant
sources. We contrast mixtures that arise from neutrino oscillations with those
signaling neutrino decays. We stress the importance of measuring fluxes in neutrino observatories.Comment: 9 RevTeX pages, 4 figure
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