No abstract

Astrophysical sources of ultrahigh energy neutrinos yield tau neutrino fluxes due to neutrino oscillations. We study in detail the contribution of tau neutrinos with energies above PeV relative to the contribution of the other flavors. We consider several different initial neutrino fluxes and include tau neutrino regeneration in transit through the Earth and energy loss of charged leptons. We discuss signals of tau neutrinos in detectors such as IceCube, RICE and ANITA.Comment: 27 pages, 19 figure

pucker, Phys. Rev. Lett. 16, 746 (1966).A number of experimental studies have been made of the momentum dependence of the total cross section for the reaction ir'p -AK° in the region of incident pion momentum extending from threshold up to and beyond that corresponding to the thresholds for H°K° and Z"if + production. 1 " 8 These studies have sought to clarify the mechanism for AK production near threshold, to search for new resonances, and to find evidence for the predicted cusplike behavior of the total cross section in the region of the UK thresholds. A limitation in previously published studies has been imposed by the uncertainty in the incident pion momentum, typically ±2%, which places a lower limit on the characteristic width of detectable structure of ~20 MeV/c. In the present experiment, the width of detectable structure in the momentum dependence of the total cross section for AK production is reduced to ±1 MeV/c by the use of a spark-chamber spectrometer in the incident pion beam. This apparatus, described elsewhere, 9 permits determination of the momentum of individual incident pions with a relative precision better than ±0.1 %, and with an absolute calibration obtained from kinematic event fitting near the A°K° and H°K° thresholds.

Acoustic pulses generated by the passage of 30-GeV protons through water show evidence for the presence of a nonthermal source. In addition to the bipolar leading-compression signal expected from thermal shock, a tripolar leading-rarefaction component is observed. The component is dominant at 4øC, where the thermal signal should vanish. A space-charge effect may be the source of this component, since other proposed mechanisms leading to tripolar pulses should give a leading-compression signal.

We study ultrahigh energy astrophysical neutrinos and the contribution of tau neutrinos from neutrino oscillations, relative to the contribution of the other flavors. We show the effect of tau neutrino regeneration and tau energy loss as they propagate through the Earth. We consider a variety of neutrino fluxes, such as cosmogenic neutrinos and neutrinos that originate in Active Galactic Nuclei. We discuss signals of tau neutrinos in detectors such as IceCube, RICE and ANITA.