4 research outputs found
Earth-skimming UHE Tau Neutrinos at the Fluorescence Detector of Pierre Auger Observatory
Ultra high energy neutrinos are produced by the interaction of hadronic
cosmic rays with the cosmic radiation background. More exotic scenarios like
topological defects or new hadrons predict even larger fluxes. In particular,
Earth-skimming tau neutrinos could be detected by the Fluorescence Detector
(FD) of Pierre Auger Observatory. A detailed evaluation of the expected number
of events has been performed for a wide class of neutrino flux models. An
updated computation of the neutrino-nucleon cross section and of the tau energy
losses has been carried out. For the most optimistic theoretical models, about
one Earth-skimming neutrino event is expected in several years at FD.Comment: 26 pages, 13 figures, version accepted for publication on
Astroparticle Physic
Upper Bounds on the Neutrino-Nucleon Inelastic Cross Section
Extraterrestrial neutrinos can initiate deeply developing air showers, and
those that traverse the atmosphere unscathed may produce cascades in the ice or
water. Up to now, no such events have been observed. This can be translated
into upper limits on the diffuse neutrino flux. On the other hand, the
observation of cosmic rays with primary energies > 10^{10} GeV suggests that
there is a guaranteed flux of cosmogenic neutrinos, arising from the decay of
charged pions (and their muon daughters) produced in proton interactions with
the cosmic microwave background. In this work, armed with these cosmogenic
neutrinos and the increased exposure of neutrino telescopes we bring up-to-date
model-independent upper bounds on the neutrino-nucleon inelastic cross section.
Uncertainties in the cosmogenic neutrino flux are discussed and taken into
account in our analysis. The prospects for improving these bounds with the
Pierre Auger Observatory are also estimated. The unprecedented statistics to be
collected by this experiment in 6 yr of operation will probe the
neutrino-nucleon inelastic cross section at the level of Standard Model
predictions.Comment: To be published in JCA
The Particle Physics Reach of High-Energy Neutrino Astronomy
We discuss the prospects for high-energy neutrino astronomy to study particle
physics in the energy regime comparable to and beyond that obtainable at the
current and planned colliders. We describe the various signatures of
high-energy cosmic neutrinos expected in both neutrino telescopes and air
shower experiments and discuss these measurements within the context of
theoretical models with a quantum gravity or string scale near a TeV,
supersymmetry and scenarios with interactions induced by electroweak
instantons. We attempt to access the particle physics reach of these
experiments.Comment: Mini-review article for New Journal of Physics, "Focus on Neutrinos"
issue. 27 pages, 11 figure