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Browsing by Author "Xu, D.L."

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    Development of a general analysis and unfolding scheme and its application to measure the energy spectrum of atmospheric neutrinos with IceCube
    (Springer, 2015) IceCube Collaboration; Palczewski, T.; Pepper, J.A.; Toale, P.A.; Williams, D.R.; Xu, D.L.; Zarzhitsky, P.; RWTH Aachen University; University of Adelaide; University of Alaska System; University of Alaska Anchorage; Clark Atlanta University; University System of Georgia; Georgia Institute of Technology; Southern University System; Southern University & A&M College; University of California System; University of California Berkeley; United States Department of Energy (DOE); Lawrence Berkeley National Laboratory; Humboldt University of Berlin; Ruhr University Bochum; University of Wurzburg; University of Bonn; Universite Libre de Bruxelles; Vrije Universiteit Brussel; Chiba University; University of Canterbury; University System of Maryland; University of Maryland College Park; University System of Ohio; Ohio State University; University of Copenhagen; Niels Bohr Institute; Dortmund University of Technology; University of Alberta; University of Erlangen Nuremberg; University of Geneva; Ghent University; University of California Irvine; University of Kansas; University of Wisconsin System; University of Wisconsin Madison; Johannes Gutenberg University of Mainz; University of Mons; Technical University of Munich; University of Delaware; University of Oxford; South Dakota School Mines & Technology; Oskar Klein Centre; Stockholm University; State University of New York (SUNY) System; State University of New York (SUNY) Stony Brook; Sungkyunkwan University (SKKU); University of Toronto; University of Alabama Tuscaloosa; Pennsylvania Commonwealth System of Higher Education (PCSHE); Pennsylvania State University; Pennsylvania State University - University Park; Uppsala University; University of Wuppertal; Helmholtz Association; Deutsches Elektronen-Synchrotron (DESY)
    We present the development and application of a generic analysis scheme for the measurement of neutrino spectra with the IceCube detector. This scheme is based on regularized unfolding, preceded by an event selection which uses a Minimum Redundancy Maximum Relevance algorithm to select the relevant variables and a random forest for the classification of events. The analysis has been developed using IceCube data from the 59-string configuration of the detector. 27,771 neutrino candidates were detected in 346 days of livetime. A rejection of 99.9999% of the atmospheric muon background is achieved. The energy spectrum of the atmospheric neutrino flux is obtained using the TRUEE unfolding program. The unfolded spectrum of atmospheric muon neutrinos covers an energy range from 100 GeV to 1 PeV. Compared to the previous measurement using the detector in the 40-string configuration, the analysis presented here, extends the upper end of the atmospheric neutrino spectrum by more than a factor of two, reaching an energy region that has not been previously accessed by spectral measurements.
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    Search for dark matter annihilation in the Galactic Center with IceCube-79
    (Springer, 2015) IceCube Collaboration; Palczewski, T.; Pepper, J.A.; Toale, P.A.; Williams, D.R.; Xu, D.L.; Zarzhitsky, P.; RWTH Aachen University; University of Adelaide; University of Alaska System; University of Alaska Anchorage; Clark Atlanta University; University System of Georgia; Georgia Institute of Technology; Southern University System; Southern University & A&M College; University of California System; University of California Berkeley; United States Department of Energy (DOE); Lawrence Berkeley National Laboratory; Humboldt University of Berlin; Ruhr University Bochum; University of Wurzburg; University of Bonn; Universite Libre de Bruxelles; Vrije Universiteit Brussel; Chiba University; University of Canterbury; University System of Maryland; University of Maryland College Park; University System of Ohio; Ohio State University; University of Copenhagen; Niels Bohr Institute; Dortmund University of Technology; Michigan State University; University of Alberta; University of Erlangen Nuremberg; University of Geneva; Ghent University; University of California Irvine; University of Kansas; University of Wisconsin System; University of Wisconsin Madison; Johannes Gutenberg University of Mainz; University of Mons; Technical University of Munich; University of Delaware; Yale University; University of Oxford; Drexel University; South Dakota School Mines & Technology; Oskar Klein Centre; Stockholm University; State University of New York (SUNY) System; State University of New York (SUNY) Stony Brook; Sungkyunkwan University (SKKU); University of Toronto; University of Alabama Tuscaloosa; Pennsylvania Commonwealth System of Higher Education (PCSHE); Pennsylvania State University; Pennsylvania State University - University Park; Uppsala University; University of Wuppertal; Helmholtz Association; Deutsches Elektronen-Synchrotron (DESY)
    The Milky Way is expected to be embedded in a halo of dark matter particles, with the highest density in the central region, and decreasing density with the halo-centric radius. Dark matter might be indirectly detectable at Earth through a flux of stable particles generated in dark matter annihilations and peaked in the direction of the Galactic Center. We present a search for an excess flux of muon (anti-) neutrinos from dark matter annihilation in the Galactic Center using the cubic-kilometer-sized IceCube neutrino detector at the South Pole. There, the Galactic Center is always seen above the horizon. Thus, new and dedicated veto techniques against atmospheric muons are required to make the southern hemisphere accessible for IceCube. We used 319.7 live-days of data from IceCube operating in its 79-string configuration during 2010 and 2011. No neutrino excess was found and the final result is compatible with the background. We present upper limits on the self-annihilation cross-section, \(\langle \sigma_A \nu \rangle\), for WIMP masses ranging from 30 GeV up to 10 TeV, assuming cuspy (NFW) and flat-cored (Burkert) dark matter halo profiles, reaching down to \(\simeq 4 \cdot 10^{-24} cm^3 s^{-1}\), and \(\simeq 2.6 \cdot 10^{-23} cm^3 s^{-1}\) for the \(\upsilon{\overline{\upsilon}}\) channel, respectively.