We report on a search for electro-magnetic and/or hadronic showers (cascades) induced by high-energy neutrinos in the data collected with the AMANDA II detector during the year 2000. The observed ...event rates are consistent with the expectations for atmospheric neutrinos and muons. We place upper limits on a diffuse flux of extraterrestrial electron, tau and muon neutrinos. A flux of neutrinos with a spectrum Φ∝E−2 which consists of an equal mix of all flavors, is limited to E2Φ(E)=8.6×10−7 GeVcm−2s−1sr−1 at a 90% confidence level for a neutrino energy range 50 TeV to 5 PeV. We present bounds for specific extraterrestrial neutrino flux predictions. Several of these models are ruled out.
A search for an excess of muon–neutrinos from neutralino annihilations in the Sun has been performed with the AMANDA-II neutrino detector using data collected in 143.7 days of live-time in 2001. No ...excess over the expected atmospheric neutrino background has been observed. An upper limit at 90% confidence level has been obtained on the annihilation rate of captured neutralinos in the Sun, as well as the corresponding muon flux limit at the Earth, both as functions of the neutralino mass in the range 100–5000
GeV.
Data taken during 1997 with the AMANDA-B10 detector are searched for a diffuse flux of neutrinos of all flavors with energies above 1016eV. At these energies the Earth is opaque to neutrinos, and ...thus neutrino induced events are concentrated at the horizon. The background are large muon bundles from down-going atmospheric air shower events. No excess events above the background expectation are observed and a neutrino flux following E−2, with an equal mix of all flavors, is limited to E2Φ(1015eV<E<3×1018eV)⩽0.99×10−6GeVcm−2s−1sr−1 at 90% confidence level. This is the most restrictive experimental bound placed by any neutrino detector at these energies. Bounds to specific extraterrestrial neutrino flux predictions are also presented.
Several models of minimum-bias hadronic interactions at ultra-high energy that have been used for calculations of air showers share essential common features. In this talk I review these common ...elements and discuss some consequences. I concentrate on properties of hadron-nucleus interactions, and I use mean depth of shower maximum as a function of primary energy to illustrate my main points. I will contrast these models with models that use a more naive treatment of hadronic interactions in nuclei but which have been successfully used to interpret measurements of depth of shower maximum.
Muons and neutrinos from cosmic ray interactions in the atmosphere originate from decays of mesons in air-showers. sibyll-2.3c aims to give a precise description of hadronic interactions in the ...relevant phase space for conventional and prompt leptons in light of new accelerator data, including that from the LHC. sibyll is designed primarily as an event generator for use in simulation of extensive air showers. Because it has been tuned for forward physics as well as the central region, it can also be used to calculate inclusive fluxes. The purpose of this paper is to describe the use of sibyll-2.3c for calculation of fluxes of atmospheric leptons.
The new South Pole air shower experiment – SPASE-2 Dickinson, J.E.; Evenson, P.A.; Gaisser, T.K. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
01/2000, Letnik:
440, Številka:
1
Journal Article
Recenzirano
This paper describes a new coincidence experiment designed to improve understanding of the composition of the primary cosmic-ray beam around the knee of the spectrum. The experiment consists of an ...air shower array on the surface (SPASE-2), which works in coincidence with an array of air-Cherenkov detectors (VULCAN), and the Antarctic Muon and Neutrino Detector Array (AMANDA) deep in the ice. The experiment must cover the energy range from ∼10
14 to ∼3×10
16 eV to overlap with direct measurements at lower energy and encompass the regions of the knee and beyond in the cosmic ray spectrum.
An efficient method for calculating inclusive conventional and prompt atmospheric leptons fluxes is presented. The coupled cascade equations are solved numerically by formulating them as matrix ...equation. The presented approach is very flexible and allows the use of different hadronic interaction models, realistic parametrizations of the primary cosmic-ray flux and the Earth's atmosphere, and a detailed treatment of particle interactions and decays. The power of the developed method is illustrated by calculating lepton flux predictions for a number of different scenarios.
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