Uncertainties on Atmospheric Neutrino Flux Calculations

The strong evidence of new physics coming from atmospheric neutrino experiments has motivated a series of critical studies to test the robustness of the available flux calculations. In view of a more precise determination of the parameters of new physics, new and more refined flux calculations are in progress. Here we review the most important sources of theoretical uncertainties which affect these computations, and the attempts currently under way to improve them.Comment: Extended version of talk given at NOW2000, Conca Specchiulla, Otranto, Italy, Sep. 2000 Fig. 2 has been replace

Progresses in the validation of the FLUKA atmospheric neutrino flux calculations

The FLUKA calculation of the atmospheric neutrino fluxes have been cross-checked by comparing predictions on lepton fluxes in atmosphere to experimental data. The dependence of predicted neutrino fluxes on the shape and normalization of primary spectrum is also investigatedComment: Presented at TAUP2001 (Sep. 8-12, Assergi, Italy). 5 pages, 1 figur

A Minimal Object Oriented Real-Time Operating System in C++

Most embedded software is currently developed using the C programming language, even though its low level of abstrac- tion requires a lot of effort to the programmer. The C++ language is a better choice because: it raises the level of abstraction; it is strongly typed, so it prevents many com- mon programming mistakes; it can be made as efficient as C through fine-grained customisation of memory mechanisms; it can be easily adapted to domain-specific needs. In ad- dition, recent compilers have grown in maturity and per- formance, and the new standard considerably improves the language by introducing new concepts and an easier syntax. In this paper we present ADOK, a minimal Real-Time Op- erating System entirely written in C++ with the exception of a few lines of assembler code. It directly offers a C++ interface to the developer, and it provides a flexible schedul- ing framework which allows the developer to customise the scheduling to its needs. In particular, we implement a two- level scheduler based on Earliest Deadline First, the Stack Resource Policy protocol for sharing resources and support for mode changes. We demonstrate through examples and a small case-study that ADOK can substantially improve productivity without sacrificing on performance

A 3-Dimensional Calculation of Atmospheric Neutrino Flux

An extensive 3-dimensional Monte Carlo calculation of the atmospheric neutrino flux is in progress with the FLUKA Monte Carlo code. The results are compared to those obtained under the 1-dimensional approximation, where secondary particles and decay products are assumed to be collinear to the primary cosmic ray, as usually done in most of the already existing flux calculations. It is shown that the collinear approximation gives rise to a wrong angular distribution of neutrinos, essentially in the Sub-GeV region. However, the angular smearing introduced by the experimental inability of detecting recoils in neutrino interactions with nuclei is large enough to wash out, in practice, most of the differences between 3-dimensional and 1-dimensional flux calculations. Therefore, the use of the collinear approximation should have not introduced a significant bias in the determination of the flavor oscillation parameters in current experiments.Comment: 27 pages, 14 figures. To be submitted to Astroparticle Physics. To be submitted to Astroparticle Physic

A Monte Carlo Calculation of Atmospheric Muon and Neutrino Fluxes

Production of muons and neutrinos in cosmic ray interactions with the atmosphere has been investigated with a cascade simulation program based on Lund Monte Carlo programs. The resulting `conventional' muon and neutrino fluxes (from $\pi ,K$ decays) agree well with earlier calculations, whereas the improved charm particle treatment used in this study gives significantly lower `prompt' fluxes compared to earlier estimates. This implies better prospects for detecting very high energy neutrinos from cosmic sources.Comment: 4 pages, uuencoded and gziped ps-fil

SysRT: A Modular Multiprocessor RTOS Simulator for Early Design Space Exploration

International audienc

Comparison of 3-Dimensional and 1-Dimensional Schemes in the calculation of Atmospheric Neutrinos

A 3-dimensional calculation of atmospheric neutrinos flux is presented, and the results are compared with those of a 1-dimensional one. In this study, interaction and propagation of particles is treated in a 3-dimensional way including the curvature of charged particles due to the geomagnetic field, which is assumed to be a dipole field. The purpose of this paper is limited to the comparison of calculation schemes. The updated flux value with new interaction model and primary flux model will be reported in a separate paper. Except for nearly horizontal directions, the flux is very similar to the result of 1 dimensional calculations. However, for near-horizontal directions an enhancement of the neutrino flux is seen even at energies as high as 1 GeV. The production height of neutrinos is lower than the prediction by 1-dimensional calculation for near-horizontal directions, and is a little higher for near-vertical directions. However, the difference is not evident except for near-horizontal directions.Comment: 22 pages, 15figure

Measuring the prompt atmospheric neutrino flux with down-going muons in neutrino telescopes

In the TeV energy region and above, the uncertainty in the level of prompt atmospheric neutrinos would limit the search for diffuse astrophysical neutrinos. We suggest that neutrino telescopes may provide an empirical determination of the flux of prompt atmospheric electron and muon neutrinos by measuring the flux of prompt down-going muons. Our suggestion is based on the consideration that prompt neutrino and prompt muon fluxes at sea level are almost identical.Comment: 4 pages, 3 figure