1694798
Design and performance of the lead-concrete geiger tower array within the HEGRA experiment
Abstract The HEGRA experiment is a hybrid installation characterized by four different types of detectors (scintillator counters, open Cherenkov counters, Cherenkov telescopes and Geiger towers) located within one detector array. The Geiger towers are built with the objective to measure the local energy deposition and to reconstruct and identify muon tracks. In addition each tower may serve as an independent high resolution muon flux monitor. With these properties the Geiger towers are operating as geometric and energetic calibration instruments for the other detector components and as additional independent measurement instruments with respect to the γ-hadron separation and the measurement of the chemical composition. In this paper the design, the performance, and the basic principles of the data analysis of the lead-concrete Geiger towers are described.
109075983
Development of a new first level trigger for the surface array in the Pierre Auger Observatory based on the CycloneTM Altera® FPGA
Abstract The development of a new first level trigger for the surface array in the Pierre Auger Observatory is described. It utilizes the new Altera ® family Cyclone TM which is available since March 2003. Different from previous and the currently used design based on the APEX TM and ACEX ® families, respectively, it offers much higher capacity of logic registers and memories, a simplified board design, lower power consumption, and lower cost. The paper describes the board design, internal structures of the programming routines, various trigger implementations and test results obtained in the laboratory.
2219103
AMANDA - first running experiment to use GRID in production
The Grid technologies are in ongoing development. Using current Grid toolkits like the Globus toolkit gives one the possibility to build up virtual organizations. Although these tookits are in still under development and do not feature all functionality, they can already now be used to set up an efficient computing environment for physics collaborations with only moderate work. We discuss in this paper the use of such a computing structure in two running experiments - the AMANDA (AMANDA = Antarctic muon and neutrino detector array) neutrino telescope and the D0 experiment at Tevatron, Fermilab. One of the main features of our approach is to avoid reprogramming of the existing software which is based on several programming languages (FORTRAN, C/C++, JAVA). This was realized with software layers around the collaboration software taking care about in- and output, user notification, tracking of running jobs, etc. A further important aspect is the resolution of library dependencies, which occur when a user runs self-compiled jobs on machines, where these libraries are not installed. These dependencies are also resolved with this layers.
59354134
Qualification tests of the 11 000 photomultipliers for the Pierre Auger Observatory fluorescence detectors
We describe the test system built to perform the acceptance tests of more than 11 000 photomultiplier (PMT) tubes employed in the fluorescence detector of the Pierre Auger Observatory. The results obtained on the properties of the PMT are presented and discussed.
123338629
IceCube: A Multipurpose Neutrino Telescope
IceCube is a new high-energy neutrino telescope which will be coming online in the near future. IceCube will be capable of measuring fluxes of all three flavors of neutrino, and its peak neutrino energy sensitivity will be in the TeV–PeV range. Here, after a brief description of the detector, we describe its anticipated performance with a selection of physics topics: supernovae, extraterrestrial diffuse and point sources of neutrinos, gamma-ray bursts, neutrinos from WIMP annihilation, and cosmic ray composition.
210155517
The IceCube Neutrino Observatory VI: Neutrino Oscillations, Supernova Searches, Ice Properties
IceCube DeepCore can study atmospheric neutrino oscillations through a combination of its low energy reach, as low as about 10 GeV, and its unprecedented statistical sample, of about 150,000 triggered atmospheric muon neutrinos per year. With the diameter of the earth as a baseline, the muon neutrino disappearance minimum and tau neutrino appearance maximum are expected at about 25 GeV, which is considerably lower energy than typical IceCube neutrino events, but higher than the energies at which accelerator-based experiments have detected oscillations. νμ disappearance and ντ appearance from neutrino oscillation can be measured in IceCube DeepCore. We present here the status of the newly developed low energy reconstruction algorithms, the expected experimental signatures, and the proposed approach for such neutrino oscillation measurements. Corresponding authors: Sebastian Euler (seuler@icecube.wisc.edu), Laura Gladstone(gladstone@icecube.wisc.edu), Jason Koskinen(koskinen@psu.edu), Donglian Xu(dxu@crimson.ua.edu) III. Physikalisches Institut, RWTH Aachen University, D-52056 Aachen, Germany Dept. of Physics, University of Wisconsin, Madison, WI 53706, USA Dept. of Physics, Pennsylvania State University, University Park, PA 16802, USA Dept. of Physics and Astronomy, University of Alabama, Tuscaloosa, AL 35487, USA
16083194
Supersymmetry breaking, heterotic strings and fluxes
In this paper we consider compactifications of heterotic strings in the presence of background flux. The background metric is a T2 fibration over a K3 base times four-dimensional Minkowski space. Depending on the choice of three-form flux different amounts of supersymmetry are preserved (N=2,1,0). For supersymmetric solutions unbroken space–time supersymmetry determines all background fields except one scalar function which is related to the dilaton. The heterotic Bianchi identity gives rise to a differential equation for the dilaton which we discuss in detail for solutions preserving an N=2 supersymmetry. In this case the differential equation is of Laplace type and as a result the solvability is guaranteed.
118793721
Superloop equations in the double scaling limit
119498787
M-theory inflation from multi M5-brane dynamics
Abstract We derive inflation from M-theory on S 1 / Z 2 via the non-perturbative dynamics of N M5-branes. The open membrane instanton interactions between the M5-branes give rise to exponential potentials which are too steep for inflation individually but lead to inflation when combined together. The resulting type of inflation, known as assisted inflation, facilitates considerably the requirement of having all moduli, except the inflaton, stabilized at the beginning of inflation. During inflation the distances between the M5-branes, which correspond to the inflatons, grow until they reach the size of the S 1 / Z 2 orbifold. At this stage the M5-branes will reheat the universe by dissolving into the boundaries through small instanton transitions. Further flux and non-perturbative contributions become important at this late stage, bringing inflation to an end and stabilizing the moduli. We find that with moderate values for N, one obtains both a sufficient amount of e-foldings and the right size for the spectral index.
12509407
An international intercomparison of environmental dosimeters.
5530207
Torsional Heterotic Geometries
Abstract We construct new examples of torsional heterotic backgrounds using duality with orientifold flux compactifications. We explain how duality provides a perturbative solution to the type I/heterotic string Bianchi identity. The choice of connection used in the Bianchi identity plays an important role in the construction. We propose the existence of a much larger landscape of compact torsional geometries using string duality. Finally, we present some quantum exact metrics that correspond to NS5-branes placed on an elliptic space. These metrics describe how torus isometries are broken by NS flux.