Several experimental techniques are currently under development, to measure the expected tiny fluxes of highest energy neutrinos above 10
18 eV. Projects in different stages of realization are ...discussed here, which are based on optical and radio as well as acoustic detectors. For the detection of neutrino events in this energy range a combination of different detector concepts in one experiment seems to be most promising.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
11 × 10
9 cosmic ray muon events above 20 GeV have been collected with the L3+C detector at LEP, CERN, in 1999 and 2000. During the last year the energy, core position and direction of the air ...showers causing the observed muons could be derived for part of the data.
Preliminary results for the vertical muon flux and charge ratio depending on the muon momentum are shown. The influence of the air shower energy on the muon properties is studied. A search for muon rate increase during the solar flare of the 14
th
July 2000 is performed. Meteorological effects on cosmic ray intensity measurements are discussed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
A common challenge in many experiments in high-energy astroparticle physics is the need for sparse instrumentation in areas of 100 km2 and above, often in remote and harsh environments. All these ...arrays have similar requirements for read-out and communication, power generation and distribution, and synchronization. Within the TAXI project we are developing a transportable, modular four-station test-array that allows us to study different approaches to solve the aforementioned problems in the laboratory and in the field. Well-defined interfaces will provide easy interchange of the components to be tested and easy transport and setup will allow in-situ testing at different sites. Every station consists of three well-understood 1 m2 scintillation detectors with nanosecond time resolution, which provide an air shower trigger. An additional sensor, currently a radio antenna for air shower detection in the 100 MHz band, is connected for testing and calibration purposes. We introduce the TAXI project and report the status and performance of the first TAXI station deployed at the Zeuthen site of DESY.
Scintillating organic fibres were irradiated in a short region (1 cm length) with 70 MeV protons or 2.0 MeV electrons under time-compressed conditions. The damage process of scintillating properties ...was studied in-situ during the irradiation using two spectrometers. It was found that the dyes recover partially during the irradiation and nearly complete within a few days. The in-situ observed data are quite different from long-term radiation effects.
We report our final results from the analysis of the full high statistics sample of events of the reaction
ν
μ
+ e
− →
μ
− +
ν
c collected with the CHARM II detector in the CERN wide-band neutrino ...beam during the years 1988 to 1991. From a signal of 15758 ± 324 inverse muon decay events we derived, inthe Born approximation, a value of (16.51 ± 0.93) × 10
−42 cm
2 GeV
−1 for the asymptotic cross section slope
σ
E
ν
, in goodagreement with the Standard Model prediction of 17.23 × 10
−42 cm
2 GeV
−1. The result constrains the scalar coupling of the electron and the muon to |
g
LL
S
|
2 < 0.475 at 90% CL.
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IJS, IMTLJ, KILJ, KISLJ, NUK, SBCE, UL, UM, UPCLJ, UPUK
We report on the results of the search for extremely-high energy neutrinos with energies above 107GeV obtained with the partially (˜30%) constructed IceCube in 2007. From the absence of signal events ...in the sample of 242.1 days of effective live time, we derive a 90% C.L. model independent differential upper limit based on the number of signal events per energy decade at E2ϕνe+νμ+ντ≃1.4×10-6GeVcm-2sec-1sr-1 for neutrinos in the energy range from 3×107 to 3×109GeV.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UM
We report new bounds on electromagnetic properties of the muon neutrino obtained from a study of neutrino-electron scattering. The results are based on the analysis of differential cross section data ...collected with the CHARM II detector. The 90% C.L. limit on the magnetic moment of the muon-neutrino
μ
ν
μ
< 3 · 10
−9
μ
B
confirms limits obtained at much lower energies. The limit on the anomalous charge radius of the muon neutrino |〈
r
2〉
anom| < 6.0 · 10
−33 cm
2 im earlier results by nearly a factor three.
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IJS, IMTLJ, KILJ, KISLJ, NUK, SBCE, UL, UM, UPCLJ, UPUK
The detection of cosmic neutrinos with energies above 1017 eV got growing interest during recent years. Possible target materials for in-matter arrays of ~100 km3 size under discussion are water, ice ...and rock salt. Here we propose to investigate permafrost as an additional alternative, covering ~20% of Earth land surface and reaching down to more than 1000 m depth at certain locations. If sufficiently large attenuation lengths for radio and acoustic signals can be demonstrated by in-situ measurements, the construction of a large hybrid array within this material may be possible in the Northern hemisphere. Properties and problems of a possible location in Siberia are discussed below. Some acoustic data are compared to laboratory measurements using "artificial" permafrost.
With construction halfway complete, IceCube is already the most sensitive neutrino telescope ever built. A rearrangement of the final holes of IceCube with increased spacing has been discussed ...recently to optimize the high energy sensitivity of the detector. Extending this baseline with radio and acoustic instrumentation in the same holes could further improve the high energy response. The goal would be both to detect events and to act as a pathfinder for hybrid detection, towards a possible larger hybrid array. Simulation results for such an array are presented here.
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