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R. Abbasi,
Y. Abdou,
T. Abu-Zayyad,
J Adams,
J. A. Aguilar,
M. Ahlers,
K. Andeen,
J. Auffenberg,
X Bai,
M Baker, [......],
C. H. Wiebusch,
A. Wiedemann,
G. Wikstrom,
D R Williams,
R. Wischnewski,
H. Wissing,
K Woschnagg,
X. W. Xu,
G. Yodh,
S Yoshida
The Astrophysical Journal 02/2010; 710(1):346-359. · 6.02 Impact Factor
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R Abbasi,
Y Abdou,
T Abu-Zayyad,
J Adams,
J A Aguilar,
M Ahlers,
K Andeen,
J Auffenberg,
X Bai,
M Baker, [......],
A Wiedemann,
G Wikström,
D R Williams,
R Wischnewski,
H Wissing,
K Woschnagg,
C Xu,
X W Xu,
G Yodh,
S Yoshida
[show abstract]
[hide abstract]
ABSTRACT: Point source searches with the IceCube neutrino telescope have been restricted to one hemisphere, due to the exclusive selection of upward going events as a way of rejecting the atmospheric muon background. We show that the region above the horizon can be included by suppressing the background through energy-sensitive cuts. This improves the sensitivity above PeV energies, previously not accessible for declinations of more than a few degrees below the horizon due to the absorption of neutrinos in Earth. We present results based on data collected with 22 strings of IceCube, extending its field of view and energy reach for point source searches. No significant excess above the atmospheric background is observed in a sky scan and in tests of source candidates. Upper limits are reported, which for the first time cover point sources in the southern sky up to EeV energies.
Physical Review Letters 11/2009; 103(22):221102. · 7.37 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: Three-quarters of the 1 cubic kilometer neutrino telescope IceCube is currently taking data. Current models predict high-energy neutrino emission from transient objects like supernovae (SNe) and gammaray bursts (GRBs). To increase the sensitivity to such transient objects we have set up an optical follow-up program that triggers optical observations on multiplets of high-energy muon-neutrinos. We define multiplets as a minimum of two muon-neutrinos from the same direction (within 4 deg) that arrive within a 100 s time window. When this happens, an alert is issued to the four ROTSE-III telescopes, which immediately observe the corresponding region in the sky. Image subtraction is applied to the optical data to find transient objects. In addition, neutrino multiplets are investigated online for temporal and directional coincidence with gamma-ray satellite observations issued over the Gamma-Ray Burst Coordinate Network. An overview of the full program is given, from the online selection of neutrino events to the automated follow-up, and the resulting sensitivity to transient neutrino sources is presented for the first time. Comment: 4 pages, 2 figures, Proceedings of the 31st ICRC, Lodz, Poland, July 2009
09/2009;
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R. Abbasi,
Y. Abdou,
M. Ackermann,
J. Adams,
M. Ahlers,
K. Andeen,
J. Auffenberg,
X. Bai,
M. Baker,
S. W. Barwick, [......],
C. H. Wiebusch,
A. Wiedemann,
G. Wikström,
D. R. Williams,
R. Wischnewski,
H. Wissing,
K. Woschnagg,
X. W. Xu,
G. Yodh,
S. Yoshida
[show abstract]
[hide abstract]
ABSTRACT: The AMANDA-II detector, operating since 2000 in the deep ice at the geographic South Pole, has accumulated a large sample of atmospheric muon neutrinos in the 100 GeV to 10 TeV energy range. The zenith angle and energy distribution of these events can be used to search for various phenomenological signatures of quantum gravity in the neutrino sector, such as violation of Lorentz invariance or quantum decoherence. Analyzing a set of 5511 candidate neutrino events collected during 1387 days of livetime from 2000 to 2006, we find no evidence for such effects and set upper limits on violation of Lorentz invariance and quantum decoherence parameters using a maximum likelihood method. Given the absence of evidence for new flavor-changing physics, we use the same methodology to determine the conventional atmospheric muon neutrino flux above 100 GeV.
Physical Review D 05/2009; 79(10):102005. · 4.56 Impact Factor
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R. Abbasi,
Y. Abdou,
M. Ackermann,
J Adams,
M. Ahlers,
K. Andeen,
J. Auffenberg,
X Bai,
M Baker,
S. W. Barwick, [......],
C. H. Wiebusch,
A. Wiedemann,
G. Wikstrom,
D R Williams,
R. Wischnewski,
H. Wissing,
K Woschnagg,
X. W. Xu,
G. Yodh,
S Yoshida
Physical Review Letters 05/2009; 102(20):201302. · 7.37 Impact Factor
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R. Abbasi,
Y. Abdou,
M. Ackermann,
J Adams,
M. Ahlers,
K. Andeen,
J. Auffenberg,
X Bai,
M Baker,
S. W. Barwick, [......],
C. H. Wiebusch,
A. Wiedemann,
G. Wikstrom,
D R Williams,
R. Wischnewski,
H. Wissing,
K Woschnagg,
X. W. Xu,
G. Yodh,
S Yoshida
Physical Review D 05/2009; 79(10):102005. · 4.56 Impact Factor
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R. Abbasi,
Y. Abdou,
T. Abu-Zayyad,
J Adams,
J. A. Aguilar,
M. Ahlers,
K. Andeen,
J. Auffenberg,
X Bai,
M Baker, [......],
C. H. Wiebusch,
A. Wiedemann,
G. Wikstrom,
D R Williams,
R. Wischnewski,
H. Wissing,
K Woschnagg,
X. W. Xu,
G. Yodh,
S Yoshida
The Astrophysical Journal 03/2009; 701(2):1721-1731. · 6.02 Impact Factor
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R. Abbasi,
Y. Abdou,
M. Ackermann,
J Adams,
M. Ahlers,
K. Andeen,
J. Auffenberg,
X Bai,
M Baker,
S. W. Barwick, [......],
C. H. Wiebusch,
A. Wiedemann,
G. Wikström,
D R Williams,
R. Wischnewski,
H. Wissing,
K Woschnagg,
X. W. Xu,
G. Yodh,
S. Yoshida (Icecube Collaboration
The Astrophysical Journal 03/2009; 701(2):1721. · 6.02 Impact Factor
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R. Abbasi,
M. Ackermann,
J Adams,
M. Ahlers,
J. Ahrens,
K. Andeen,
J. Auffenberg,
X Bai,
M Baker,
B. Baret, [......],
C. H. Wiebusch,
C. Wiedemann,
G. Wikstrom,
D R Williams,
R. Wischnewski,
H. Wissing,
K Woschnagg,
X. W. Xu,
G. Yodh,
S Yoshida
Physical Review D 03/2009; 79(6):062001. · 4.56 Impact Factor
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R. Abbasi,
Y. Abdou,
M. Ackermann,
J Adams,
J. Aguilar,
M. Ahlers,
K. Andeen,
J. Auffenberg,
X Bai,
M Baker, [......],
C. H. Wiebusch,
A. Wiedemann,
G. Wikstrom,
D R Williams,
R. Wischnewski,
H. Wissing,
K Woschnagg,
X. W. Xu,
G. Yodh,
S Yoshida
The Astrophysical Journal Letters 03/2009; 701(1):L47. · 5.53 Impact Factor
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R. Abbasi,
M. Ackermann,
J. Adams,
M. Ahlers,
J. Ahrens,
K. Andeen,
J. Auffenberg,
X. Bai,
M. Baker,
S.W. Barwick, [......],
C.H. Wiebusch,
C. Wiedemann,
G. Wikström,
D.R. Williams,
R. Wischnewski,
H. Wissing,
K. Woschnagg,
X.W. Xu,
G. Yodh,
S. Yoshida
[show abstract]
[hide abstract]
ABSTRACT: IceCube is a km-scale neutrino observatory under construction at the South Pole with sensors both in the deep ice (InIce) and on the surface (IceTop). The sensors, called Digital Optical Modules (DOMs), detect, digitize and timestamp the signals from optical Cherenkov-radiation photons. The DOM Main Board (MB) data acquisition subsystem is connected to the central DAQ in the IceCube Laboratory (ICL) by a single twisted copper wire-pair and transmits packetized data on demand. Time calibration is maintained throughout the array by regular transmission to the DOMs of precisely timed analog signals, synchronized to a central GPS-disciplined clock. The design goals and consequent features, functional capabilities, and initial performance of the DOM MB, and the operation of a combined array of DOMs as a system, are described here. Experience with the first InIce strings and the IceTop stations indicates that the system design and performance goals have been achieved.
Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 03/2009; 601(3):294-316. · 1.21 Impact Factor
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J. Ahrens,
X. Bai,
G. Barouch,
S. W. Barwick,
R. C. Bay,
T. Becka,
K.-H. Becker,
D. Bertrand,
F. Binon,
A. Biron, [......],
C. Walck,
C. Weinheimer,
C. H. Wiebusch,
C. Wiedemann,
R. Wischnewski,
H. Wissing,
K. Woschnagg,
W. Wu,
G. Yodh,
S. Young
[show abstract]
[hide abstract]
ABSTRACT: This paper describes the search for astronomical sources of high-energy neutrinos using the AMANDA-B10 detector, an array of 302 photomultiplier tubes used for the detection of Cerenkov light from upward-traveling neutrino-induced muons, buried deep in ice at the South Pole. The absolute pointing accuracy and angular resolution were studied by using coincident events between the AMANDA detector and two independent telescopes on the surface, the GASP air Cerenkov telescope and the SPASE extensive air shower array. Using data collected from 1997 April to October (130.1 days of live time), a general survey of the northern hemisphere revealed no statistically significant excess of events from any direction. The sensitivity for a flux of muon neutrinos is based on the effective detection area for through-going muons. Averaged over the northern sky, the effective detection area exceeds 10,000 m2 for Eμ ≈ 10 TeV. Neutrinos generated in the atmosphere by cosmic-ray interactions were used to verify the predicted performance of the detector. For a source with a differential energy spectrum proportional to E and declination larger than +40°, we obtain E2(dNν/dE) ≤ 10-6 GeV cm-2 s-1 for an energy threshold of 10 GeV.
The Astrophysical Journal 12/2008; 583(2):1040. · 6.02 Impact Factor
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R. Abbasi,
M. Ackermann,
J Adams,
M. Ahlers,
J. Ahrens,
K. Andeen,
J. Auffenberg,
X Bai,
M Baker,
B. Baret, [......],
C. H. Wiebusch,
C. Wiedemann,
G. Wikstrom,
D R Williams,
R. Wischnewski,
H. Wissing,
K Woschnagg,
X. W. Xu,
G. Yodh,
S Yoshida
The Astrophysical Journal Letters 12/2008; 689(1):L65-L66. · 5.53 Impact Factor
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IceCube Collaboration,
A. Achterberg,
M. Ackermann,
J. Adams,
J. Ahrens,
K. Andeen,
D. W. Atlee,
J. N. Bahcall,
X. Bai,
B. Baret, [......],
C. H. Wiebusch,
G. Wikström,
D. R. Williams,
R. Wischnewski,
H. Wissing,
K. Woschnagg,
X. W. Xu,
G. Yodh,
S. Yoshida,
J. D. Zornoza
Nuclear Physics B - Proceedings Supplements 12/2007; 175:407-408. · 0.88 Impact Factor
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A. Achterberg,
M. Ackermann,
J. Adams,
J. Ahrens,
K. Andeen,
J. Auffenberg,
X. Bai,
B. Baret,
S. W. Barwick,
R. Bay, [......],
C. Wiedemann,
G. Wikström,
D. R. Williams,
R. Wischnewski,
H. Wissing,
K. Woschnagg,
X. W. Xu,
G. Yodh,
S. Yoshida,
J. D. Zornoza
[show abstract]
[hide abstract]
ABSTRACT: A search for TeV-PeV muon neutrinos from unresolved sources was performed on AMANDA-II data collected between 2000 and 2003 with an equivalent live time of 807 days. This diffuse analysis sought to find an extraterrestrial neutrino flux from sources with nonthermal components. The signal is expected to have a harder spectrum than the atmospheric muon and neutrino backgrounds. Since no excess of events was seen in the data over the expected background, an upper limit of E2Φ90%C.L.<7.4×10-8 GeV cm-2 s-1 sr-1 is placed on the diffuse flux of muon neutrinos with a Φ∝E-2 spectrum in the energy range 16 TeV to 2.5 PeV. This is currently the most sensitive Φ∝E-2 diffuse astrophysical neutrino limit. We also set upper limits for astrophysical and prompt neutrino models, all of which have spectra different from Φ∝E-2.
Phys. Rev. D. 08/2007; 76(4).
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A. Achterberg,
M. Ackermann,
J. Adams,
J. Ahrens,
K. Andeen,
J. Auffenberg,
X. Bai,
B. Baret,
S. W. Barwick,
R. Bay, [......],
C. H. Wiebusch,
G. Wikström,
D. R. Williams,
R. Wischnewski,
H. Wissing,
K. Woschnagg,
X. W. Xu,
G. Yodh,
S. Yoshida,
J. D. Zornoza
[show abstract]
[hide abstract]
ABSTRACT: The IceCube neutrino detector is a cubic kilometer TeV to PeV neutrino detector under construction at the geographic South Pole. The dominant population of neutrinos detected in IceCube is due to meson decay in cosmic-ray air showers. These atmospheric neutrinos are relatively well understood and serve as a calibration and verification tool for the new detector. In 2006, the detector was approximately 10% completed, and we report on data acquired from the detector in this configuration. We observe an atmospheric neutrino signal consistent with expectations, demonstrating that the IceCube detector is capable of identifying neutrino events. In the first 137.4 days of live time, 234 neutrino candidates were selected with an expectation of 211±76.1(syst)±14.5(stat) events from atmospheric neutrinos.
Phys. Rev. D. 07/2007; 76(2).
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A. Achterberg,
M. Ackermann,
J. Adams,
J. Ahrens,
K. Andeen,
D. W. Atlee,
J. N. Bahcall,
X. Bai,
B. Baret,
S. W. Barwick, [......],
C. H. Wiebusch,
G. Wikström,
D. R. Williams,
R. Wischnewski,
H. Wissing,
K. Woschnagg,
X. W. Xu,
G. Yodh,
S. Yoshida,
J. D. Zornoza
[show abstract]
[hide abstract]
ABSTRACT: We report the results of a five-year survey of the northern sky to search for point sources of high energy neutrinos. The search was performed on the data collected with the AMANDA-II neutrino telescope in the years 2000 to 2004, with a live time of 1001 days. The sample of selected events consists of 4282 upward going muon tracks with high reconstruction quality and an energy larger than about 100 GeV. We found no indication of point sources of neutrinos and set 90% confidence level flux upper limits for an all-sky search and also for a catalog of 32 selected sources. For the all-sky search, our average (over declination and right ascension) experimentally observed upper limit Φ0=(E/1 TeV)γ·dΦ/dE to a point source flux of muon and tau neutrino (detected as muons arising from taus) is Φνμ+ν̅ μ0+Φντ+ν̅ τ0=11.1× 10-11 TeV-1 cm-2 s-1, in the energy range between 1.6 TeV and 2.5 PeV for a flavor ratio Φνμ+ν̅ μ0/Φντ+ν̅ τ0=1 and assuming a spectral index γ=2. It should be noticed that this is the first time we set upper limits to the flux of muon and tau neutrinos. In previous papers we provided muon neutrino upper limits only neglecting the sensitivity to a signal from tau neutrinos, which improves the limits by 10% to 16%. The value of the average upper limit presented in this work corresponds to twice the limit on the muon neutrino flux Φνμ+ν̅ μ0=5.5×10-11 TeV-1 cm-2 s-1. A stacking analysis for preselected active galactic nuclei and a search based on the angular separation of the events were also performed. We report the most stringent flux upper limits to date, including the results of a detailed assessment of systematic uncertainties.
Phys. Rev. D. 05/2007; 75(10).
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B. Aharmim,
Q. R. Ahmad,
S. N. Ahmed,
R. C. Allen,
T. C. Andersen,
J. D. Anglin,
G. Bühler,
J. C. Barton,
E. W. Beier,
M. Bercovitch, [......],
J. Wendland,
N. West,
J. B. Wilhelmy,
J. F. Wilkerson,
J. R. Wilson,
P. Wittich,
J. M. Wouters,
A. Wright,
M. Yeh,
K. Zuber
[show abstract]
[hide abstract]
ABSTRACT: This article provides the complete description of results from the Phase I data set of the Sudbury Neutrino Observatory (SNO). The Phase I data set is based on a 0.65 kiloton-year exposure of 2H2O (in the following denoted as D2O) to the solar 8B neutrino flux. Included here are details of the SNO physics and detector model, evaluations of systematic uncertainties, and estimates of backgrounds. Also discussed are SNO's approach to statistical extraction of the signals from the three neutrino reactions (charged current, neutral current, and elastic scattering) and the results of a search for a day-night asymmetry in the νe flux. Under the assumption that the 8B spectrum is undistorted, the measurements from this phase yield a solar νe flux of ϕ(νe)=1.76-0.05+0.05(stat.)-0.09+0.09(syst.)×106 cm-2 s-1 and a non-νe component of ϕ(νμτ)=3.41-0.45+0.45(stat.)-0.45+0.48(syst.)×106 cm-2 s-1. The sum of these components provides a total flux in excellent agreement with the predictions of standard solar models. The day-night asymmetry in the νe flux is found to be Ae=7.0±4.9(stat.)-1.2+1.3%(syst.), when the asymmetry in the total flux is constrained to be zero.
Phys. Rev. C. 04/2007; 75(4).
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A Achterberg,
M Ackermann,
J Adams,
J Ahrens,
K Andeen,
D W Atlee,
J N Bahcall,
X Bai,
B Baret,
M Bartelt, [......],
C H Wiebusch,
G Wikström,
D R Williams,
R Wischnewski,
H Wissing,
K Woschnagg,
X W Xu,
G Yodh,
S Yoshida,
J D Zornoza
[show abstract]
[hide abstract]
ABSTRACT: On 27 December 2004, a giant gamma flare from the Soft Gamma-Ray Repeater 1806-20 saturated many satellite gamma-ray detectors, being the brightest transient event ever observed in the Galaxy. AMANDA-II was used to search for down-going muons indicative of high-energy gammas and/or neutrinos from this object. The data revealed no significant signal, so upper limits (at 90% C.L.) on the normalization constant were set: 0.05(0.5) TeV-1 m;{-2} s;{-1} for gamma=-1.47 (-2) in the gamma flux and 0.4(6.1) TeV-1 m;{-2} s;{-1} for gamma=-1.47 (-2) in the high-energy neutrino flux.
Physical Review Letters 01/2007; 97(22):221101. · 7.37 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: Kilometer-scale deep under-ice or -water Cherenkov neutrino detectors may detect muon and electron neutrinos from astrophysical sources at energies of a TeV and above. Tau neutrinos are also expected from these sources due to neutrino flavor oscillations in vacuum, and tau neutrinos are free of atmospheric background at a much lower energy than muon and electron neutrinos. Identification of tau neutrinos is expected to be possible above the PeV energy range through the "double bang" and "lollipop" signatures. We discuss another signature of tau in the PeV-EeV range, arising from the decay of tau leptons inside the detector to much brighter muons.
09/2006;
