53001696
Design and performance of the South Pole Acoustic Test Setup
The South Pole Acoustic Test Setup (SPATS) was built to evaluate the acoustic characteristics of the South Pole ice in the 10-100 kHz frequency range, for the purpose of assessing the feasibility o ...
40898720
A fast embedded system for radio detection of cosmic rays
For the detection of radio signals from ultra high energy (> 1017 eV) cosmic rays in the frequency range up to 80 MHz an embedded system was designed, built, and tested. A steep band-pass filter in the range of 30 to 80 MHz suppresses the main source of radio frequency interferences. To fulfill the data acquisition (DAQ) task, four 180 MHz twelve bit ADCs have to be read-out by a FPGA into a two gigabyte buffer memory. Furthermore the FPGA contains the trigger and a Altera NIOS II soft-core processor for data management. A GPS receiver controls the timing of the system. For the read-out an Ethernet-link and a CAN interface to a WLAN communication board is foreseen. The architecture of the system and the measured performance of the DAQ-board 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.
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
120215184
A search for gamma radiation above 24 TeV energy from cosmic point sources
Abstract The HEGRA collaboration has searched for γ-ray emission from 36 potential cosmic point sources with the wide angle air Cerenkov detector AIROBICC which is part of the HEGRA cosmic ray detector complex on La Palma. AIROBICC has a γ-ray energy threshold of around 24 TeV and a mean angular resolution of 0.29 °. None of the sources could be found. Upper limits to their fluxes are given. For the VHE γ-ray emitters, the Crab nebula and Mrk 421, these flux limits are below those extrapolated from lower energy observations. Our lower limit for Mrk 421 might be interpreted either as being due to an energy cut-off in the acceleration mechanism or to the onset of γ-interaction with photons of the universal infrared background.
124085377
Geometric Transitions, Non-Kahler Geometries and String Vacua
We summarize an explicit construction of a duality cycle for geometric transitions in type II and heterotic theories. We emphasize that the manifolds with torsion constructed with this duality cycle are crucial for understanding different phenomena appearing in effective field theories.
17056116
A two-loop test of M(atrix) theory
Abstract We consider the scattering of two Dirichlet zero-branes in M(atrix) theory. Using the formulation of M(atrix) theory in terms of ten-dimensional super Yang-Mills theory dimensionally reduced to (0+1) dimensions, we obtain the effective (velocity-dependent) potential describing these particles. At one loop we obtain the well-known result for the leading order of the effective potential V eff ∼ v 4 / r 7 , where v and r are the relative velocity and distance between the two zero-branes, respectively. A calculation of the effective potential at two loops shows that no renormalizations of the v 4 term of the effective potential occur at this order.
124628585
Long-term stability of film, TLD, and other integrating dosimeters in warm and humid climates
8126330
Supersymmetry breaking, M-theory and fluxes
We consider warped compactifications of Script M-theory to three-dimensional Minkowski space on compact eight-manifolds. Taking all the leading quantum gravity corrections of eleven-dimensional supergravity into account we obtain the solution to the equations of motion and Bianchi identities. Generically these vacua are not supersymmetric and yet have a vanishing three-dimensional cosmological constant.
118125996
Moduli Stabilization and String Geometry
I describe recent progress in using conformal field theory techniques to describe the stabilization of moduli fields arising in compactifications of type IIB string theory to four dimensions.