2050309
A prototype detector for directional measurement of the cosmogenic neutron flux
This paper describes a novel directional neutron detector. The low pressure time projection chamber uses a mix of helium and CF4 gases. The detector reconstructs the energy and angular distribution of fast neutron recoils. This paper reports results of energy calibration using an source and angular reconstruction studies using a collimated neutron source. The best performance is obtained with a 12.5% CF4 { 87.5% He gas mixture. At low energies the target for fast neutrons transitions is primarily helium, while at higher energies, the uorine contributes as a target. The reconstruction eciency is both energy and target dependent. For neutrons with energies less than 20 MeV, the reconstruction eciency is 40% for uorine recoils and 60% for helium recoils.
13999234
Recent Results on Neutrino Oscillations
This article reviews the many new results from neutrino oscillation searches which were presented at ICHEP '98. Exciting indications of neutrino oscillations have been seen in the solar neutrino deficit, atmospheric neutrino deficit and LSND excess. These indications and reported limits on oscillations are considered. Attempts to develop a theory which addresses all of the neutrino oscillation data are discussed. Some of the remaining questions and the future experiments which will help answer these questions are described.
119757503
A review of experimental results on neutrino oscillations
118385577
Measurements of the rates of forward jet production in deep inelastic muon scattering
118381753
A Study of the Fluorescence Response of Tetraphenyl-butadiene
Tetraphenyl-butadiene (TPB) is a widely used fluorescent wavelength-shifter. A common application is in liquid-argon-based particle detectors, where scintillation light is produced in the UV at 128 nm. In liquid argon experiments, TPB is often employed to shift the scintillation light to the visible range in order to allow detection via standard photomultiplier tubes. This paper presents studies on the stability of TPB with time under exposure to light. We also examine batch-to-batch variations. We compare scintillation-grade TPB to 99% pure TPB response. In the 99% pure samples, we report a yellowing effect, and full degradation of the TPB emission-peak, upon extended exposure to light.
208856461
Search for core-collapse supernovae using the MiniBooNE neutrino detector
We present a search for core-collapse supernovae in the Milky Way galaxy, using the MiniBooNE neutrino detector. No evidence is found for core-collapse supernovae occurring in our Galaxy in the period from December 14, 2004 to July 31, 2008, corresponding to 98% live time for collection. We set a limit on the core-collapse supernova rate out to a distance of 13.4 kpc to be less than 0.69 supernovae per year at 90% C.L.
46124610
Beam Test Performance and Simulation of Prototypes for the ALICE Silicon Pixel Detector
The silicon pixel detector (SPD) of the ALICE experiment in preparation at the Large Hadron Collider (LHC) at CERN is designed to provide the precise vertex reconstruction needed for measuring heavy flavor production in heavy ion collisions at very high energies and high multiplicity. The SPD forms the innermost part of the Inner Tracking System (ITS) which also includes silicon drift and silicon strip detectors. Single assembly prototypes of the ALICE SPD have been tested at the CERN SPS using high energy proton/pion beams in 2002 and 2003. We report on the experimental determination of the spatial precision. We also report on the first combined beam test with prototypes of the other ITS silicon detector technologies at the CERN SPS in November 2004. The issue of SPD simulation is briefly discussed.
53326002
Muon Track Reconstruction and Data Selection Techniques in AMANDA
The Antarctic Muon And Neutrino Detector Array (AMANDA) is a high-energy neutrino telescope operating at the geographic South Pole. It is a lattice of photo-multiplier tubes buried deep in the polar ice between 1500 and 2000 m. The primary goal of this detector is to discover astrophysical sources of high-energy neutrinos. A high-energy muon neutrino coming through the earth from the Northern Hemisphere can be identified by the secondary muon moving upward through the detector. The muon tracks are reconstructed with a maximum likelihood method. It models the arrival times and amplitudes of Cherenkov photons registered by the photo-multipliers. This paper describes the different methods of reconstruction, which have been successfully implemented within AMANDA. Strategies for optimizing the reconstruction performance and rejecting background are presented. For a typical analysis procedure the direction of tracks are reconstructed with about 2° accuracy. © 2004 Elsevier B.V. All rights reserved.
16708071
Limits, discovery and cut optimization for a Poisson process with uncertainty in background and signal efficiency: TRolke 2.0
A C++ class was written for the calculation of frequentist confidence intervals using the profile likelihood method. Seven combinations of Binomial, Gaussian, Poissonian and Binomial uncertainties are implemented. The package provides routines for the calculation of upper and lower limits, sensitivity and related properties. It also supports hypothesis tests which take uncertainties into account. It can be used in compiled C++ code, in Python or interactively via the ROOT analysis framework.
118237340
Response of AMANDA-II to Cosmic Ray Muons
The high flux of down-going muon detected by the AMANDA-II neutrino telescope is used as a test beam to check the experiment systematics and to improve the knowledge of its response. This work shows the result of the effort to get a better understanding of AMANDA-II performance, an improved data filter and event reconstruction. The preliminary experimental down-going muon angular and depth intensities are compared with Monte Carlo prediction, other experimental results and theoretical calculations. A good agreement is found within systematic uncertainties.
15092137
Detecting Dark Matter annihilation lines with Fermi
Dark matter constitutes one of the most intriguing but so far unresolved issues in physics today. In many extensions of the Standard Model the existence of a stable Weakly Interacting Massive Particle (WIMP) is predicted. The WIMP is an excellent dark matter particle candidate and one of the most interesting scenarios include an annihilation of two WIMPs into two gamma-rays. If the WIMPs are assumed to be non-relativistic, the resulting photons will both have an energy equal to the mass of the WIMP and manifest themselves as a monochromatic spectral line in the energy spectrum. This type of signal would represent a 'smoking gun' for dark matter, since no other known astrophysical process should be able to produce it. In these proceedings we give an overview of the different approaches to a search for dark matter lines that the Fermi-LAT collaboration is pursuing and the various challenges involved.