871 research outputs found
Ultra High Energy Neutrino-Relic Neutrino Interactions In Dark Halos to Solve Infrared-Tev And GZK Cut-Off
Ultra High Energy Neutrino scattering on Relic Light Neutrinos in Dark
Galactic or Local Group lead to Z and WW,ZZ showering: the nucleon component of
the shower may overcome the GZK cut-off while the electro-magnetic tail at TeVs
up to EeVs energy may solve the Infrared-TeV cut-off in a natural way.
Different Gamma TeV puzzles may find a solution within this scenario: new
predictions on UHECR spectra in future data are derived.Comment: 4 pages, 3 figures, 2 tables ICRC 2001 HE 3.6 Dark Matter - German
Why Tau First?
Electron neutrino has been the first neutral lepton to be foreseen and
discovered last century. The un-ordered muon and its neutrino arose later by
cosmic rays. The tau discover, the heaviest, the most unstable charged lepton,
was found surprisingly on 1975. Its neutrino was hardly revealed just on 2000.
So why High Energy Neutrino Astronomy should rise first via tau neutrino, the
last, the most rare one? The reasons are based on a chain of three favorable
coincidences found last decade: the neutrino masses and their flavor mixing,
the UHECR opacity on Cosmic Black Body (GZK cut off on BBR), the amplified tau
air-shower decaying in flight. Indeed guaranteed UHE GZK tau neutrinos, feed by
muon mixing, while skimming the Earth might lead to boosted UHE tau, mostly
horizontal ones. These UHE lepton decay in flight are spread, amplified, noise
free Air-Shower: a huge event for an unique particle. To be observed soon:
within Auger sky, in present decade. Its discover may sign of the first tau
appearance.Comment: 8 pages, 4 figure
Upward Tau Air Showers from Earth
We estimate the rate of observable Horizontal and Upward Tau Air-Showers
(HORTAUs, UPTAUS) considering both the Earth opacity and the finite size of the
terrestrial atmosphere. We calculate the effective target volumes and masses
for Tau air-showers emerging from the Earth. The resulting model-independent
masses for satellite experiments such as EUSO may encompass at E_nu_tau = 10^19
eV a very large volume, V= 1020 km^3. Adopting simple power law neutrino
fluxes, E^-2 and E^-1, calibrated to GZK-like and Z-Burst-like models, we
estimate that at E= 10^19 eV nearly half a dozen horizontal shower events
should be detected by EUSO in three years of data collection by the
"guaranteed" GZK neutrino flux. We also find that the equivalent mass for an
Earth outer layer made of rock is dominant compared to the water, contrary to
simplified all-rock/all-water Earth models and previous Montecarlo simulations.
Therefore we expect an enhancement of neutrino detection along continental
shelves nearby the highest mountain chains, also given the better geometrical
acceptance for Earth skimming neutrinos. The Auger experiment might reveal such
a signature at E_nu= 10^{18} eV (with 26 events in 3 yr) towards the Andes, if
the angular resolution at the horizon (both in azimuth and zenith) would reach
an accuracy of nearly one degree needed to disentangle tau air showers from
common UHECR. The number of events increases at lower energies; therefore we
suggest an extension of the EUSO and Auger sensitivity down to (or even below)
E_nu = 10^19 eV and E_nu = 10^18 eV respectively.Comment: New version resubmitted to ApJ on the 6th April 2004; 55 Pages,20
figures, major changes following referee reques
UHECR narrow clustering correlating IceCube through-going muons
The recent UHECR events by AUGER and the Telescope Array (TA) suggested that
wide clusterings as the North and South, named Hot Spot, are related to near
AGNs such as the one in M82 and Cen A. In the same frame since 2008 we assumed
that the UHECR are made by light and lightest nuclei to explain the otherwise
embarrassing absence of the huge nearby Virgo cluster, absence due to the
fragility and the opacity of lightest nuclei by photo-dissociation from Virgo
distances. Moreover UHECR map exhibits a few narrow clustering, some near the
galactic plane, as toward SS 433 and on the opposite side of the plane at
celestial horizons: we tagged them in 2014 suggesting possible near source
active also as a UHE neutrino. Indeed since last year, 2015, highest IceCube
trough-going muons, UHE up-going neutrino events at hundreds TeV energy, did
show (by two cases over three tagged in North sky) the expected overlapping of
UHE neutrinos signals with narrow crowding UHECR. New data with higher energy
threshold somehow re-confirmed our preliminary proposal; new possible sources
appear by a additional correlated UHE-neutrino versus UHE-neutrino and-or with
narrow UHECR clustering events. A possible role of relic neutrino mass
scattering by ZeV neutrino arised.Comment: 6 pages, 5 figure
Tramas escolares y tecnología : experiencias en diálogo
La comunicación versa sobre las tramas didácticas construidas con tecnología en aulas de Mendoza. Hablamos del entretejido didáctico que implica tareas y actividades que enfrentan los estudiantes, experiencias y modos de construcción del conocimiento junto a la tecnología. La trama didáctica potencia y proyecta habilidades específicas en el uso y apropiación de las TIC. ¿Cómo enseñan los docentes y cómo aprenden los alumnos con tecnologías en el aula? La metodología usada en el estudio ha sido cuanti-cualitativa. Algunas conclusiones se vinculan con las posibilidades de innovar, considerando que la innovación da cuenta de habilidades profesionales personales que el docente desarrolla para adaptarse a situaciones cambiantes o diferentes (IIPE . UNESCO, 2007) y que supone aprender profesionalmente, promover y fortificar el equipo docente, propiciar y contribuir creativamente con estudiantes, pares y directivos.Fil: Aguirre, Jimena Isabel. Universidad Nacional de Cuyo.Fil: Lucentini, Natalia. Universidad Nacional de Cuyo
Shadows of Relic Neutrino Masses and Spectra on Highest Energy GZK Cosmic Rays
The Ultra High Energy (UHE) neutrino scattering onto relic cosmic neutrinos
in galactic and local halos offers an unique way to overcome GZK cut-off. The
UHE nu secondary of UHE photo-pion decays may escape the GZK cut-off and travel
on cosmic distances hitting local light relic neutrinos clustered in dark
halos. The Z resonant production and the competitive W^+W^-, ZZ pair production
define a characteristic imprint on hadronic consequent UHECR spectra. This
imprint keeps memory both of the primary UHE nu spectra as well as of the
possible relic neutrino masses values, energy spectra and relic densities. Such
an hadronic showering imprint should reflect into spectra morphology of cosmic
rays near and above GZK 10^{19}-10^{21}eV cut-off energies. A possible neutrino
degenerate masses at eVs or a more complex and significant neutrino mass split
below or near Super-Kamiokande \triangle m_{\nu_{SK}}= 0.1 eV masses might be
reflected after each corresponding Z peak showering, into new twin unexpected
UHECR flux modulation behind GZK energies: E_{p} sim 3(frac{triangle
m_{\nu_{SK}}}/m_{\nu}10^{21}),eV.
Other shadowsof lightest, nearly massless, neutrinos m_{nu_{2K} simeq 0.001eV
simeq kT_{\nu}, their lowest relic temperatures, energies and densities might
be also reflected at even higher energies edges near Grand Unification: E_{p}
\sim 2.2(m_{\nu_{2K}/E_{\nu}})10^{23}, eV .Comment: 14 pages, 6 Figures,Invited Talk Heidelberg DARK 200
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