The IceCube Neutrino Observatory I: Point Source Searches

Searches for point sources of astrophysical neutrinos and related measurements: Searches for steady and time-variable sources; Follow-up programs; AGNs; GRBs; Moon shadow; Submitted papers to the 32nd International Cosmic Ray Conference, Beijing 2011.Comment: Papers submitted by the IceCube Collaboration to the 32nd International Cosmic Ray Conference, Beijing 2011; part

The IceCube Neutrino Observatory V: Future Developments

Proposed enhancements of the IceCube observatory. Submitted papers to the 32nd International Cosmic Ray Conference, Beijing 2011.Comment: Papers submitted by the IceCube Collaboration to the 32nd International Cosmic Ray Conference, Beijing 2011; part

The IceCube Neutrino Observatory IV: Searches for Dark Matter and Exotic Particles

Exotic particle searches: WIMPs annihilating in the Sun, in the galactic center, in nearby dwarf galaxies; magnetic monopoles; Submitted papers to the 32nd International Cosmic Ray Conference, Beijing 2011.Comment: Papers submitted by the IceCube Collaboration to the 32nd International Cosmic Ray Conference, Beijing 2011; part I

Measurement of the Multi-TeV Neutrino Interaction Cross-Section with IceCube Using Earth Absorption

Neutrinos interact only very weakly, so they are extremely penetrating. The theoretical neutrino–nucleon interaction cross-section, however, increases with increasing neutrino energy, and neutrinos with energies above 40 teraelectronvolts (TeV) are expected to be absorbed as they pass through the Earth. Experimentally, the cross-section has been determined only at the relatively low energies (below 0.4 TeV) that are available at neutrino beams from accelerators1,2. Here we report a measurement of neutrino absorption by the Earth using a sample of 10,784 energetic upward-going neutrino-induced muons. The flux of high-energy neutrinos transiting long paths through the Earth is attenuated compared to a reference sample that follows shorter trajectories. Using a fit to the two-dimensional distribution of muon energy and zenith angle, we determine the neutrino–nucleon interaction cross-section for neutrino energies 6.3–980 TeV, more than an order of magnitude higher than previous measurements. The measured cross-section is about 1.3 times the prediction of the standard model3, consistent with the expectations for charged- and neutral-current interactions. We do not observe a large increase in the cross-section with neutrino energy, in contrast with the predictions of some theoretical models, including those invoking more compact spatial dimensions4 or the production of leptoquarks5. This cross-section measurement can be used to set limits on the existence of some hypothesized beyond-standard-model particles, including leptoquarks

Search for Sterile Neutrino Mixing Using Three Years of Icecube Deepcore Data

We present a search for a light sterile neutrino using three years of atmospheric neutrino data from the DeepCore detector in the energy range of approximately 10–60 GeV. DeepCore is the low-energy subarray of the IceCube Neutrino Observatory. The standard three-neutrino paradigm can be probed by adding an additional light sterile neutrino. Sterile neutrinos do not interact through the standard weak interaction and, therefore, cannot be directly detected. However, their mixing with the three active neutrino states leaves an imprint on the standard atmospheric neutrino oscillations for energies below 100 GeV. A search for such mixing via muon neutrino disappearance is presented here. The data are found to be consistent with the standard three-neutrino hypothesis. Therefore, we derive limits on the mixing matrix elements at the level of (90% C.L.) for the sterile neutrino mass splitting

The IceCube Neutrino Observatory III: Cosmic Rays

Cosmic rays and related measurements: IceTop overview; IceTop calibration; Cosmic ray composition; Air shower measurements; Studies of cosmic ray muons; Studies of PeV gamma rays; Cosmic ray anisotropy; Forbush decrease; Submitted papers to the 32nd International Cosmic Ray Conference, Beijing 2011.Comment: Papers submitted by the IceCube Collaboration to the 32nd International Cosmic Ray Conference, Beijing 2011; part II