13036601
Search for active neutrino disappearance using neutral-current interactions in the MINOS long-baseline experiment.
We report the first detailed comparisons of the rates and spectra of neutral-current neutrino interactions at two widely separated locations. A depletion in the rate at the far site would indicate mixing between nu(mu) and a sterile particle. No anomalous depletion in the reconstructed energy spectrum is observed. Assuming oscillations occur at a single mass-squared splitting, a fit to the neutral- and charged-current energy spectra limits the fraction of nu(mu) oscillating to a sterile neutrino to be below 0.68 at 90% confidence level. A less stringent limit due to a possible contribution to the measured neutral-current event rate at the far site from nu(e) appearance at the current experimental limit is also presented.
29520771
Search for magnetic monopoles with the Soudan 2 detector.
A search for grand unified theory magnetic monopoles making highly ionizing tracks in argon gas has been conducted using the Soudan 2 nucleon decay detector. This underground detector is a large fine-grained tracking calorimeter comprised of long drift tubes read out by proportional wires. No monopole candidates were observed in data taken over almost three years, yielding an upper flux limit of 8.7{times}10{sup {minus}15} cm{sup {minus}2}s{sup {minus}1}sr{sup {minus}1} for monopole velocities of {beta}{gt}2{times}10{sup {minus}3}.
110729769
ATLAS pixel detector electronics and sensors
The silicon pixel tracking system for the ATLAS experiment at the Large Hadron Collider is described and the performance requirements are summarized. Detailed descriptions of the pixel detector electronics and the silicon sensors are given. The design, fabrication, assembly and performance of the pixel detector modules are presented. Data obtained from test beams as well as studies using cosmic rays are also discussed.
12668582
The Pierre Auger Observatory V : Enhancements
The southern Pierre Auger Observatory was designed to detect ultrahig h energy cosmic rays above 10 eV with high accuracy exploiting a hybrid detection technique. A surface arra y of 1660 water Cherenkov detectors on a 1500 m triangular grid covers an area of 3000 km. The atmosphere above the array is viewed by 24 wide angle telescopes. These telescopes observe the faint fluorescence light of the extensive air showers at dark moonless nights, i.e. with a duty cycle of about 15 %. As an enhancement to this baseline design o f the Auger Observatory three additional telescopes with elevated field of view were built and now constitute HEAT, the h igh-elevation Auger telescopes. These telescopes are similar to the 24 other fluorescence telescopes (FD) but c an be tilted by29 degrees upward. They cover an elevation range from30 to 58 degrees above horizon to enable the unbiased detection of nearby low en ergy air showers. Especially in combination with the detector information from an infill array of w ater tanks on a750m grid close to the HEAT site the energy range of high quality hybrid air shower measuremen ts is extended down to below 10 eV. HEAT is fully commissioned and is taking data continuously since September 2009. The status and prospects of HEAT are discussed and first (preliminary) data are presented.
118469809
Underground muons observed in the Soudan 2 detector from the directions of x-ray sources
We report on observations of underground muons made with the Soudan 2 proton decay detector at a depth of 2090 mwe from the directions of the binaries Hercules X-1 and 1E2259+586 and the Crab pulsar.
41110005
Ultrahigh energy cosmic ray composition from surface air shower and underground muon measurements at Soudan 2.
The Soudan 2 experiment has performed time-coincident cosmic ray air shower and underground muon measurements. Comparisons to Monte Carlo predictions show that such measurements can make statistically significant tests of the primary composition in the knee region of the cosmic ray spectrum. The results do not support any significant increase in the average primary mass with energy in the range of {similar_to}10{sup 4} TeV per nucleus. Some systematic uncertainties remain, however, particularly in the Monte Carlo modeling of the cosmic ray shower.
120187847
Clebsch‐Gordan Coefficients and Special Function Identities. I. The Harmonic Oscillator Group
It is shown that by constructing explicit realizations of the Clebsch‐Gordan decomposition for tensor products of irreducible representations of a group G, one can derive a wide variety of special function identities with physical interest. In this paper, the representation theory of the harmonic oscillator group is used to give elegant derivations of identities involving Hermite, Laguerre, Bessel, and hypergeometric functions.
116316991
Lie theory and separation of variables. 8. Semisubgroup coordinates for Psi tt - Delta 2Psi = 0
15532764
Quadrics on complex Riemannian spaces of constant curvature, separation of variables, and the Gaudin magnet
Integrable systems that are connected with orthogonal separation of variables in complex Riemannian spaces of constant curvature are considered herein. An isomorphism with the hyperbolic Gaudin magnet, previously pointed out by one of the authors, extends to coordinates of this type. The complete classification of these separable coordinate systems is provided by means of the corresponding L matrices for the Gaudin magnet. The limiting procedures (or e calculus) which relate various degenerate orthogonal coordinate systems play a crucial role in the classification of all such systems.
55017968
Series solutions for the Dirac equation in Kerr-Newman space-time
The Dirac equation is solved for an electron in a Kerr–Newman geometry using an adaptation of the procedure of Chandrasekhar. The corresponding eigenfunctions obtained can be represented as series of Jacobi polynomials. The spectrum of eigenvalues can be calculated using continued fraction techniques. Representations for the eigenvalues and eigenfunctions are obtained for various ranges of the parameters appearing in the Kerr–Newman metric. Some comments concerning the bag model of nucleons are made.
121892369
Lie theory and the wave equation in space–time. I. The Lorentz group
In this article we begin a study of the relationship between separation of variables and the conformal symmetry group of the wave equation ψtt −Δ3ψ=0 in space–time. In this first article we make a detailed study of separation of variables for the Laplace operator on the one and two sheeted hyperboloids in Minkowski space. We then restrict ourselves to homogeneous solutions of the wave equation and the Lorentz subgroup SO(3,1) of the conformal group SO(4,2). We study the various separable bases by using the methods of integral geometry as developed by Gel’fand and Graev. In most cases we give the spectral analysis for these bases, and a number of new bases are developed in detail. Many of the special function identities derived appear to be new. This preliminary study is of importance when we subsequently study models of the Hilbert space structure for solutions of the wave equation and the Klein–Gordon equation ψtt−Δ3ψ=λψ.