1,821 research outputs found
Search for CP violation in the lepton sector
One of the major open issues in neutrino physics is the possible existence of
CP violation in the neutrino sector. Such an observation would have an
important impact in various domains of physics, from high energy physics to
cosmology. Its search requires future accelerator neutrino facilities producing
intense and pure neutrino beams such as "beta-beams". Here we review the
different beta-beam scenarios proposed so far and discuss the present status,
with a particular emphasis on the original baseline scenario and its
feasibility. Alternative strategies for the CP violation search are to be
pursued as well. A possibility is to search for CP violation effects in
astrophysical environments. Here we present recent analytical and numerical
results obtained in the context of core-collapse supernovae. In particular, we
point out the conditions under which there can be CP violating effects in dense
media and show numerical results on the supernova (anti-)neutrino fluxes and on
the electron fraction, relevant for the r-process nucleosynthesis.Comment: 12 page
Recent advances in neutrino astrophysics
Neutrinos are produced by a variety of sources that comprise our Sun,
explosive environments such as core-collapse supernovae, the Earth and the
Early Universe. The precise origin of the recently discovered ultra-high energy
neutrinos is to be determined yet. These weakly interacting particles give us
information on their sources, although the neutrino fluxes can be modified when
neutrinos traverse an astrophysical environment. Here we highlight recent
advances in neutrino astrophysics and emphasise the important progress in our
understanding of neutrino flavour conversion in media.Comment: Proceedings for the Symposium "Frontiers of Fundamental Physics
2014", July 15-18, Marseille, 8 pages, 1 figur
Neutrino flavour conversion and supernovae
We summarize the recent developments in our understanding of neutrino flavour
conversion in core-collapse supernovae and discuss open questions.Comment: Proceedings to the "Eleventh Conference on the Intersections of
Particle and Nuclear Physics (CIPANP2012)", May 29 to June 3, Florida, 8
pages, 2 figure
Theoretical developments in supernova neutrino physics : mass corrections and pairing correlators
We highlight the progress in our understanding of how neutrinos change their
flavor in astrophysical environments, in particular effects from the neutrino
self-interaction. We emphasize extended descriptions of neutrino propagation in
massive stars that are beyond the current one based on the mean-field
approximation. The extended equations include, in particular, corrections from
(anti)neutrino-(anti)neutrino pairing correlations and from the neutrino mass.
We underline open issues and challenges.Comment: 5 pages, Proceedings for the TAUP 2015 conferenc
Low energy neutrino scattering : from fundamental interaction studies to astrophysics
Neutrino scattering at low energies is essential for a variety of timely
applications potentially having fundamental implications, e.g. unraveling
unknown neutrino properties, such as the third neutrino mixing angle, the
detection of the diffuse supernova neutrino background, or of cosmological
neutrinos and furnishing a new constraint to double-beta decay calculations.
Here we discuss some applications, the present status and the perspectives.Comment: 6 pages, Proceedings to the 45th Winter School in Theoretical Physics
"Neutrino Interactions: from Theory to Monte Carlo Simulations", Ladek-Zdroj,
Poland, February 2--11, 200
The neutrino spectral split in core-collapse supernovae: a magnetic resonance phenomenon
A variety of neutrino flavour conversion phenomena occur in core-collapse
supernova, due to the large neutrino density close to the neutrinosphere, and
the importance of the neutrino-neutrino interaction. Three different regimes
have been identified so far, usually called the synchronization, the bipolar
oscillations and the spectral split. Using the formalism of polarization
vectors, within two-flavours, we focus on the spectral split phenomenon and we
show for the first time that the physical mechanism underlying the neutrino
spectral split is a magnetic resonance phenomenon. In particular, we show that
the precession frequencies fulfill the magnetic resonance conditions. Our
numerical calculations show that the neutrino energies and the location at
which the resonance takes place in the supernova coincide well with the
neutrino energies at which a spectral swap occurs. The corresponding
adiabaticity parameters present spikes at the resonance location.Comment: 11 pages, 9 figures, text and references adde
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