James Brack

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Construction of the first stage of the Pierre Auger Observatory has begun. The aim of the Observatory is to collect unprecedented information about cosmic rays above 10 18 eV: The first phase of the project, the construction and operation of a prototype system, known as the engineering array, has now been completed. It has allowed all of the subsystems that(More)
iii Abstract In early 2010, the Long-Baseline Neutrino Experiment (LBNE) science collaboration initiated a study to investigate the physics potential of the experiment with a broad set of different beam, near-and far-detector configurations. Nine initial topics were identified as scientific areas that motivate construction of a long-baseline neutrino(More)
Using data collected at the Pierre Auger Observatory during the past 3.7 years, we demonstrated a correlation between the arrival directions of cosmic rays with energy above 6 x 10(19) electron volts and the positions of active galactic nuclei (AGN) lying within approximately 75 megaparsecs. We rejected the hypothesis of an isotropic distribution of these(More)
1 Abstract Polarized leptoproduction of charm is an experimentally completely unexplored and theoretically very interesting topic. Of particular interest in this area is the potential sensitivity of the polarization asymmetry to the contribution of the gluons to the nucleon spin. The present HERMES spectrometer is far from optimal for detecting the most(More)
Production and decay angular distributions were extracted from measurements of exclusive electroproduction of the ρ 0 (770) meson over a range in the virtual photon negative four-momentum squared 0.5 < Q 2 < 4 GeV 2 and the photon-nucleon invariant mass range 3.8 < W < 6.5 GeV. The experiment was performed with the Hermes spectrometer, using a(More)
Energy-dependent patterns in the arrival directions of cosmic rays are searched for using data of the Pierre Auger Observatory. We investigate local regions around the highest-energy cosmic rays with E ≥ 6×10 19 eV by analyzing cosmic rays with energies above E ≥ 5×10 18 eV arriving within an angular separation of approximately 15 •. We characterize the(More)
The addition of O 2 to gas mixtures in time projection chambers containing CS 2 has recently been shown to produce multiple negative ions that travel at slightly different velocities. This allows a measurement of the absolute position of ionis-ing events in the z (drift) direction. In this work, we apply the z-fiducialization technique to a directional dark(More)