http://particle.astro.ru.nl/pub/JPPNP63-293.pdf

Cosmic rays from the knee to the highest energies

Design and Initial Performance of the Askaryan Radio Array Prototype EeV Neutrino Detector at the South Pole

We report new limits on cosmic neutrino fluxes from the test flight of the Antarctic Impulsive Transient Antenna (ANITA) experiment, which completed an 18.4 day flight of a prototype long-duration balloon payload, called ANITA-lite, in early 2004. We search for impulsive events that could be associated with ultrahigh energy neutrino interactions in the ice and derive limits that constrain several models for ultrahigh energy neutrino fluxes and rule out the long-standing Z-burst model.

https://kuscholarworks.ku.edu/bitstream/handle/1808/1357/GetPDFServlet1.pdf;sequence=1

Constraints on cosmic neutrino fluxes from the Antarctic impulsive transient antenna experiment

We discuss the propagation of muons of energy above a TeV through rock and stress the importance of correctly accounting for the fluctuations of the energy loss in radiative processes. Accounting for these fluctuations affects the major types of underground muon fluxes in the opposite way from a naive treatment that neglects the muon straggling. The rates of downward atmospheric muons are increased, while the flux of upward neutrino-induced muons is decreased. The paper analyzes the causes of these effects and gives helpful parametrizations for the muon ranges applicable to the two types of muon rates. We also extend our calculations to muon energies of ${10}^{6}$ TeV and discuss the uncertainties in the muon energy loss at extremely high energy. An appendix gives a short review of the analytic techniques used to solve the problem of straggling and presents a toy model that displays the role of fluctuations in muon propagation. In another appendix we introduce an interesting technique for the generation of approximate energy, angular, and lateral distributions from the muon survival probability.

Propagation of Multi TeV Muons

We calculate the flux of neutrinos generated by the propagation of ultrahigh energy nuclei over cosmological distances. The propagation takes into account the interactions with cosmic background radiations including the CMB and the most recent estimates of higher energy (infrared, optical, and ultraviolet) backgrounds. We assume that the composition of ultrahigh energy cosmic rays (UHECRs) at the source is the same as the one observed at low energies. This assumption fits the present data well at the highest energies. We compare the cosmogenic neutrino flux from mixed composition sources to that from pure proton sources. We find that the neutrino flux in the mixed composition case has a high energy peak, mainly due to photopion production off CMB photons, of similar shape and amplitude to those in the proton case. At low energies both composition cases have significant neutrino flux with a peak around 1014.5 eV due to the higher energy backgrounds. The mixed composition case induces a higher flux of neutrinos at energies below 1013 eV due to the neutron decay component that extends down to low energies. Detection of diffuse neutrino fluxes at ultrahigh energies can strongly constrain the source distribution of UHECRs whereas fluxes at lower energies could be used to constrain confinement of VHE and UHE cosmic rays if combined with composition analysis from cosmic ray experiments.

http://iopscience.iop.org/article/10.1088/1475-7516/2006/09/005/pdf

A. Leonardi

Papers

Earth-skimming UHE tau neutrinos at the fluorescence detector of Pierre Auger Observatory