Browsing by Author "Nakarmi, P."

Now showing 1 - 5 of 5
  • Thumbnail Image
    Item
    Constraints on Minute-Scale Transient Astrophysical Neutrino Sources
    (American Physical Society, 2019-02-06) Aartsen, M. G.; Ackermann, M.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Ahrens, M.; Al Samarai, I.; Altmann, D.; Andeen, K.; Anderson, T.; Ansseau, I.; Anton, G.; Arguelles, C.; Auffenberg, J.; Axani, S.; Backes, P.; Bagherpour, H.; Bai, X.; Barbano, A.; Barron, J. P.; Barwick, S. W.; Baum, V.; Bay, R.; Beatty, J. J.; Tjus, J. Becker; Becker, K. -H.; BenZvi, S.; Berley, D.; Bernardini, E.; Besson, D. Z.; Binder, G.; Bindig, D.; Blaufuss, E.; Blot, S.; Bohm, C.; Boerner, M.; Bos, F.; Boeser, S.; Botner, O.; Bourbeau, E.; Bourbeau, J.; Bradascio, F.; Braun, J.; Brenzke, M.; Bretz, H. -P.; Bron, S.; Brostean-Kaiser, J.; Burgman, A.; Busse, R. S.; Carver, T.; Cheung, E.; Chirkin, D.; Christov, A.; Clark, K.; Classen, L.; Collin, G. H.; Conrad, J. M.; Coppin, P.; Correa, P.; Cowen, D. F.; Cross, R.; Dave, P.; Day, M.; de Andre, J. P. A. M.; De Clercq, C.; DeLaunay, J. J.; Dembinski, H.; Deoskar, K.; De Ridder, S.; Desiati, P.; de Vries, K. D.; de Wasseige, G.; de With, M.; DeYoung, T.; Diaz-Velez, J. C.; di Lorenzo, V.; Dujmovic, H.; Dumm, J. P.; Dunkman, M.; Dvorak, E.; Eberhardt, B.; Ehrhardt, T.; Eichmann, B.; Eller, P.; Evans, P. A.; Evenson, P. A.; Fahey, S.; Fazely, A. R.; Felde, J.; Filimonov, K.; Finley, C.; Franckowiak, A.; Friedman, E.; Fritz, A.; Gaisser, T. K.; Gallagher, J.; Ganster, E.; Gerhardt, L.; Ghorbani, K.; Giang, W.; Glauch, T.; Gluesenkamp, T.; Goldschmidt, A.; Gonzalez, J. G.; Grant, D.; Griffith, Z.; Haack, C.; Hallgren, A.; Halve, L.; Halzen, F.; Hanson, K.; Hebecker, D.; Heereman, D.; Helbing, K.; Hellauer, R.; Hickford, S.; Hignight, J.; Hill, G. C.; Hoffman, K. D.; Hoffmann, R.; Hoinka, T.; Hokanson-Fasig, B.; Hoshina, K.; Huang, F.; Huber, M.; Hultqvist, K.; Huennefeld, M.; Hussain, R.; In, S.; Iovine, N.; Ishihara, A.; Jacobi, E.; Japaridze, G. S.; Jeong, M.; Jero, K.; Jones, B. J. P.; Kalaczynski, P.; Kang, W.; Kappes, A.; Kappesser, D.; Karg, T.; Karle, A.; Katz, U.; Kauer, M.; Keivani, A.; Kelley, J. L.; Kheirandish, A.; Kim, J.; Kintscher, T.; Kiryluk, J.; Kittler, T.; Klein, S. R.; Koirala, R.; Kolanoski, H.; Koepke, L.; Kopper, C.; Kopper, S.; Koschinsky, J. P.; Koskinen, D. J.; Kowalski, M.; Krings, K.; Kroll, M.; Krueckl, G.; Kunwar, S.; Kurahashi, N.; Kyriacou, A.; Labare, M.; Lanfranchi, J. L.; Larson, M. J.; Lauber, F.; Leonard, K.; Leuermann, M.; Liu, Q. R.; Lohfink, E.; Mariscal, C. J. Lozano; Lu, L.; Lunemann, J.; Luszczak, W.; Madsen, J.; Maggi, G.; Mahn, K. B. M.; Makino, Y.; Mancina, S.; Maris, I. C.; Maruyama, R.; Mase, K.; Maunu, R.; Meagher, K.; Medici, M.; Meier, M.; Menne, T.; Merino, G.; Meures, T.; Miarecki, S.; Micallef, J.; Momente, G.; Montaruli, T.; Moore, R. W.; Moulai, M.; Nagai, R.; Nahnhauer, R.; Nakarmi, P.; Naumann, U.; Neer, G.; Niederhausen, H.; Nowicki, S. C.; Nygren, D. R.; Pollmann, A. Obertacke; Olivas, A.; O'Murchadha, A.; Osborne, J. P.; O'Sullivan, E.; Palczewski, T.; Pandya, H.; Pankova, D. V.; Peiffer, P.; Pepper, J. A.; de los Heros, C. Perez; Pieloth, D.; Pinat, E.; Pizzuto, A.; Plum, M.; Price, P. B.; Przybylski, G. T.; Raab, C.; Rameez, M.; Rauch, L.; Rawlins, K.; Rea, I. C.; Reimann, R.; Relethford, B.; Renzi, G.; Resconi, E.; Rhode, W.; Richman, M.; Robertson, S.; Rongen, M.; Rott, C.; Ruhe, T.; Ryckbosch, D.; Rysewyk, D.; Safa, I.; Herrera, S. E. Sanchez; Sandrock, A.; Sandroos, J.; Santander, M.; Sarkar, S.; Sarkar, S.; Satalecka, K.; Schaufel, M.; Schlunder, P.; Schmidt, T.; Schneider, A.; Schneider, J.; Schoeneberg, S.; Schumacher, L.; Sclafani, S.; Seckel, D.; Seunarine, S.; Soedingrekso, J.; Soldin, D.; Song, M.; Spiczak, G. M.; Spiering, C.; Stachurska, J.; Stamatikos, M.; Stanev, T.; Stasik, A.; Stein, R.; Stettner, J.; Steuer, A.; Stezelberger, T.; Stokstad, R. G.; Stossl, A.; Strotjohann, N. L.; Stuttard, T.; Sullivan, G. W.; Sutherland, M.; Taboada, I.; Tenholt, F.; Ter-Antonyan, S.; Terliuk, A.; Tilav, S.; Toale, P. A.; Tobin, M. N.; Tonnis, C.; Toscano, S.; Tosi, D.; Tselengidou, M.; Tung, C. F.; Turcati, A.; Turley, C. F.; Ty, B.; Unger, E.; Elorrieta, M. A. Unland; Usner, M.; Vandenbroucke, J.; Van Driessche, W.; van Eijk, D.; van Eijndhoven, N.; Vanheule, S.; van Santen, J.; Vraeghe, M.; Walck, C.; Wallace, A.; Wallraff, M.; Wandler, F. D.; Wandkowsky, N.; Watson, T. B.; Waza, A.; Weaver, C.; Weiss, M. J.; Wendt, C.; Werthebach, J.; Westerhoff, S.; Whelan, B. J.; Whitehorn, N.; Wiebe, K.; Wiebusch, C. H.; Wille, L.; Williams, D. R.; Wills, L.; Wolf, M.; Wood, J.; Wood, T. R.; Woolsey, E.; Woschnagg, K.; Wrede, G.; Xu, D. L.; Xu, X. W.; Yanez, J. P.; Yodh, G.; Yoshida, S.; Yuan, T.; RWTH Aachen University; University of Adelaide; University of Alaska System; University of Alaska Anchorage; University of Texas System; University of Texas Arlington; 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; Universite Libre de Bruxelles; Vrije Universiteit Brussel; Massachusetts Institute of Technology (MIT); 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 Leicester; University of California Los Angeles; University of Wisconsin System; University of Wisconsin Madison; Johannes Gutenberg University of Mainz; Marquette University; Technical University of Munich; University of Munster; University of Delaware; Yale University; University of Oxford; Drexel University; South Dakota School Mines & Technology; University of Rochester; 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 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); University of Tokyo
    High-energy neutrino emission has been predicted for several short-lived astrophysical transients including gamma-ray bursts (GRBs), core-collapse supernovae with choked jets, and neutron star mergers. IceCube's optical and x-ray follow-up program searches for such transient sources by looking for two or more muon neutrino candidates in directional coincidence and arriving within 100 s. The measured rate of neutrino alerts is consistent with the expected rate of chance coincidences of atmospheric background events and no likely electromagnetic counterparts have been identified in Swift follow-up observations. Here, we calculate generic bounds on the neutrino flux of short-lived transient sources. Assuming an E-2.5 neutrino spectrum, we find that the neutrino flux of rare sources, like long gamma-ray bursts, is constrained to < 5% of the detected astrophysical flux and the energy released in neutrinos (100 GeV to 10 PeV) by a median bright GRB-like source is < 10(52.5) erg. For a harder E-2.13 neutrino spectrum up to 30% of the flux could be produced by GRBs and the allowed median source energy is < 10(52) erg. A hypothetical population of transient sources has to be more common than 10(-5) Mpc(-3) yr(-1) (5 x 10(-8) Mpc(-3) yr(-1) for the E-2.13 spectrum) to account for the complete astrophysical neutrino flux.
  • Thumbnail Image
    Item
    Measurement of atmospheric tau neutrino appearance with IceCube DeepCore
    (American Physical Society, 2019) IceCube Collaboration; Kopper, S.; Nakarmi, P.; Santander, M.; Williams, D.R.; RWTH Aachen University; University of Adelaide; University of Alaska System; University of Alaska Anchorage; University of Texas System; University of Texas Arlington; Clark Atlanta University; University System of Georgia; Georgia Institute of Technology; 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; Universite Libre de Bruxelles; Vrije Universiteit Brussel; Massachusetts Institute of Technology (MIT); 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; Technical University of Munich; University of Geneva; Ghent University; University of California Irvine; University of Kansas; University of California Los Angeles; University of Wisconsin System; University of Wisconsin Madison; Johannes Gutenberg University of Mainz; Marquette University; University of Munster; University of Delaware; Yale University; University of Oxford; Drexel University; South Dakota School Mines & Technology; University of Rochester; Oskar Klein Centre; Stockholm University; State University of New York (SUNY) System; State University of New York (SUNY) Stony Brook; Sungkyunkwan University (SKKU); 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); University of Alabama Tuscaloosa
    We present a measurement of atmospheric tau neutrino appearance from oscillations with three years of data from the DeepCore subarray of the IceCube Neutrino Observatory. This analysis uses atmospheric neutrinos from the full sky with reconstructed energies between 5.6 and 56 GeV to search for a statistical excess of cascadelike neutrino events which are the signature of \({\nu }_{\tau }\) interactions. For \(\mathrm{CC}+\mathrm{NC}\) (CC-only) interactions, we measure the tau neutrino normalization to be \({0.73}_{-0.24}^{+0.30}\) (\({0.57}_{-0.30}^{+0.36}\)) and exclude the absence of tau neutrino oscillations at a significance of \(3.2\sigma \) (\(2.0\sigma \)) These results are consistent with, and of similar precision to, a confirmatory IceCube analysis also presented, as well as measurements performed by other experiments.
  • Thumbnail Image
    Item
    Search for neutrinos from dark matter self-annihilations in the center of the Milky Way with 3 years of IceCube/DeepCore
    (Springer, 2017) IceCube Collaboration; Kopper, S.; Nakarmi, P.; Pepper, J.A.; Toale, P.A.; Williams, D.R.; RWTH Aachen University; University of Adelaide; University of Alaska System; University of Alaska Anchorage; University of Texas System; University of Texas Arlington; 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; Universite Libre de Bruxelles; Vrije Universiteit Brussel; Massachusetts Institute of Technology (MIT); 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; Marquette University; University of Mons; Technical University of Munich; University of Munster; University of Delaware; Yale University; University of Oxford; Drexel University; South Dakota School Mines & Technology; University of Rochester; 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 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); University of Tokyo
    We present a search for a neutrino signal from dark matter self-annihilations in the Milky Way using the IceCube Neutrino Observatory (IceCube). In 1005 days of data we found no significant excess of neutrinos over the background of neutrinos produced in atmospheric air showers from cosmic ray interactions. We derive upper limits on the velocity averaged product of the dark matter self-annihilation cross section and the relative velocity of the dark matter particles \(\langle \sigma_A v\rangle\). Upper limits are set for dark matter particle candidate masses ranging from 10 GeV up to 1 TeV while considering annihilation through multiple channels. This work sets the most stringent limit on a neutrino signal from dark matter with mass between 10 and 100 GeV, with a limit of 1.18 · 10⁻²³ cm³ s⁻¹ for 100 GeV dark matter particles self-annihilating via τ⁺τ⁻ to neutrinos (assuming the Navarro-Frenk-White dark matter halo profile).
  • Thumbnail Image
    Item
    Search for steady point-like sources in the astrophysical muon neutrino flux with 8 years of IceCube data
    (Springer, 2019) IceCube Collaboration; Kopper, S.; Nakarmi, P.; Santander, M.; Williams, D.R.; RWTH Aachen University; University of Adelaide; University of Alaska System; University of Alaska Anchorage; University of Texas System; University of Texas Arlington; 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; Universite Libre de Bruxelles; Vrije Universiteit Brussel; Massachusetts Institute of Technology (MIT); 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 California Los Angeles; University of Wisconsin System; University of Wisconsin Madison; Johannes Gutenberg University of Mainz; Marquette University; Technical University of Munich; University of Munster; University of Delaware; Yale University; University of Oxford; Drexel University; South Dakota School Mines & Technology; University of Rochester; 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 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); University of Tokyo
    The IceCube Collaboration has observed a high-energy astrophysical neutrino flux and recently found evidence for neutrino emission from the blazar TXS 0506 \(+\) 056. These results open a new window into the high-energy universe. However, the source or sources of most of the observed flux of astrophysical neutrinos remains uncertain. Here, a search for steady point-like neutrino sources is performed using an unbinned likelihood analysis. The method searches for a spatial accumulation of muon-neutrino events using the very high-statistics sample of about 497,000 neutrinos recorded by IceCube between 2009 and 2017. The median angular resolution is \(\sim {1}^{\circ }\) at 1 TeV and improves to \(\sim 0.{3}^{\circ }\) for neutrinos with an energy of 1 PeV. Compared to previous analyses, this search is optimized for point-like neutrino emission with the same flux-characteristics as the observed astrophysical muon-neutrino flux and introduces an improved event-reconstruction and parametrization of the background. The result is an improvement in sensitivity to the muon-neutrino flux compared to the previous analysis of \(\sim 35%\) assuming an \({E}^{-2}\) spectrum. The sensitivity on the muon-neutrino flux is at a level of \({E}^{2}dN/dE=3·{10}^{-13}\phantom{\rule{0.166667em}{0ex}}\mathrm{TeV}\phantom{\rule{0.166667em}{0ex}}{\mathrm{cm}}^{-2}\phantom{\rule{0.166667em}{0ex}}{s}^{-1}\). No new evidence for neutrino sources is found in a full sky scan and in an a priori candidate source list that is motivated by gamma-ray observations. Furthermore, no significant excesses above background are found from populations of sub-threshold sources. The implications of the non-observation for potential source classes are discussed.
  • Thumbnail Image
    Item
    Velocity independent constraints on spin-dependent DM-nucleon interactions from IceCube and PICO
    (Springer, 2020) IceCube Collaboration; Kopper, S.; Nakarmi, P.; Santander, M.; Williams, D.R.; University of Canterbury; Helmholtz Association; Deutsches Elektronen-Synchrotron (DESY); Universite Libre de Bruxelles; University of Copenhagen; Niels Bohr Institute; Oskar Klein Centre; Stockholm University; University of Geneva; Marquette University; Pennsylvania Commonwealth System of Higher Education (PCSHE); Pennsylvania State University; Pennsylvania State University - University Park; University of Erlangen Nuremberg; Massachusetts Institute of Technology (MIT); RWTH Aachen University; South Dakota School Mines & Technology; Karlsruhe Institute of Technology; University of California System; University of California Irvine; Johannes Gutenberg University of Mainz; University of California Berkeley; University System of Ohio; Ohio State University; University of Wuppertal; Ruhr University Bochum; University of Wurzburg; University of Rochester; University System of Maryland; University of Maryland College Park; University of Kansas; United States Department of Energy (DOE); Lawrence Berkeley National Laboratory; Dortmund University of Technology; Uppsala University; University of Wisconsin System; University of Wisconsin Madison; University of Munster; University System of Georgia; Georgia Institute of Technology; Sungkyunkwan University (SKKU); University of Delaware; Vrije Universiteit Brussel; Ghent University; Humboldt University of Berlin; Michigan State University; Southern University System; Southern University & A&M College; Technical University of Munich; University of Alberta; University of Adelaide; Chiba University; Clark Atlanta University; University of Texas System; University of Texas Arlington; State University of New York (SUNY) System; State University of New York (SUNY) Stony Brook; University of Alabama Tuscaloosa; Drexel University; Yale University; Mercer University; University of Alaska System; University of Alaska Anchorage; University of Oxford; University of California Los Angeles; Queens University - Canada; Universitat Politecnica de Valencia; Pacific Northwest National Laboratory; Northwestern University; University of Chicago; Indiana University System; Indiana University South Bend; Fermi National Accelerator Laboratory; Universidad Nacional Autonoma de Mexico; Saha Institute of Nuclear Physics; Laurentian University; Czech Technical University Prague; Universite de Montreal; Virginia Polytechnic Institute & State University; Brookhaven National Laboratory; Atomic Energy of Canada Limited; Argonne National Laboratory; National Research Nuclear University MEPhI (Moscow Engineering Physics Institute)
    Adopting the Standard Halo Model (SHM) of an isotropic Maxwellian velocity distribution for dark matter (DM) particles in the Galaxy, the most stringent current constraints on their spin-dependent scattering cross-section with nucleons come from the IceCube neutrino observatory and the PICO-60 \({\text{C}}_{3}{\text{F}}_{8}\) superheated bubble chamber experiments. The former is sensitive to high energy neutrinos from the self-annihilation of DM particles captured in the Sun, while the latter looks for nuclear recoil events from DM scattering off nucleons. Although slower DM particles are more likely to be captured by the Sun, the faster ones are more likely to be detected by PICO. Recent N-body simulations suggest significant deviations from the SHM for the smooth halo component of the DM, while observations hint at a dominant fraction of the local DM being in substructures. We use the method of Ferrer et al. (JCAP 1509: 052, 2015) to exploit the complementarity between the two approaches and derive conservative constraints on DM-nucleon scattering. Our results constrain \({\sigma }_{\mathrm{SD}}\lesssim 3×{10}^{-39}{\mathrm{cm}}^{2}\) ( \(6×{10}^{-38}{\mathrm{cm}}^{2}\) ) at \(\gtrsim 90%\) C.L. for a DM particle of mass 1 TeV annihilating into \({\tau }^{+}{\tau }^{-}\) ( \(b\overline{b}\) ) with a local density of \({\rho }_{\mathrm{DM}}=0.3\phantom{\rule{3.33333pt}{0ex}}{\mathrm{GeV}/\mathrm{cm}}^{3}\). The constraints scale inversely with \({\rho }_{\mathrm{DM}}\) and are independent of the DM velocity distribution.