Showing papers on "Neutrino detector published in 2003"
01 Apr 2003-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: Super-Kamiokande is the world's largest water Cherenkov detector, with net mass 50,000 tons as discussed by the authors, which collected 1678 live-days of data, observing neutrinos from the Sun, Earth's atmosphere, and the K2K long-baseline neutrino beam with high efficiency.
Abstract: Super-Kamiokande is the world's largest water Cherenkov detector, with net mass 50,000 tons. During the period April, 1996 to July, 2001, Super-Kamiokande I collected 1678 live-days of data, observing neutrinos from the Sun, Earth's atmosphere, and the K2K long-baseline neutrino beam with high efficiency. These data provided crucial information for our current understanding of neutrino oscillations, as well as setting stringent limits on nucleon decay. In this paper, we describe the detector in detail, including its site, configuration, data acquisition equipment, online and offline software, and calibration systems which were used during Super-Kamiokande I.
708 citations
TL;DR: Distortions of cosmic microwave background temperature and polarization maps caused by gravitational lensing, observable with high angular resolution and high sensitivity, can be used to measure the neutrino mass.
Abstract: Distortions of cosmic microwave background temperature and polarization maps caused by gravitational lensing, observable with high angular resolution and high sensitivity, can be used to measure the neutrino mass. Assuming two massless species and one with mass m(nu), we forecast sigma(m(nu))=0.15 eV from the Planck satellite and sigma(m(nu))=0.04 eV from observations with twice the angular resolution and approximately 20 times the sensitivity. A detection is likely at this higher sensitivity since the observation of atmospheric neutrino oscillations requires Deltam(2)(nu) greater, similar (0.04 eV)(2).
201 citations
TL;DR: In this paper, it was shown that a sterile neutrino with mass in the 1-20 keV range and a small mixing with electron neutrinos can simultaneously explain the origin of the pulsar motions and the dark matter in the universe.
Abstract: We show that a sterile neutrino with mass in the 1-20 keV range and a small
mixing with the electron neutrino can simultaneously explain the origin of the
pulsar motions and the dark matter in the universe. An asymmetric neutrino
emission from a hot nascent neutron star can be the explanation of the observed
pulsar velocities. In addition to the pulsar kick mechanism based on resonant
neutrino transitions, we point out a new possibility: an asymmetric
off-resonant emission of sterile neutrinos. The two cases correspond to
different values of the masses and mixing angles. In both cases we identify the
ranges of parameters consistent with the pulsar kick, as well as cosmological
constraints.
194 citations
TL;DR: In this paper, the authors proposed a method for optimising experimental cuts in order to place the strongest constraints (upper limits) on theoretical signal models, which relies only on signal and background expectations derived from Monte Carlo simulations, so no bias is introduced by looking at actual data.
162 citations
KEK1
TL;DR: A next generation water Cherenkov detector at Kamioka with a total mass of ~1 Mton is called Hyper-Kamiokande as discussed by the authors, which will allow to extend nucleon decay search to τp/B(p → e+π0) > 1035yr and $\tau_p/b(p\to\bar{
u}K^+)>10^{34}~{\rm yr}$.
Abstract: A next generation water Cherenkov detector at Kamioka with a total mass of ~1 Mton is called Hyper-Kamiokande. If the beam intensity of a 50-GeV proton synchrotron now under construction at Tokai is upgraded to 4 MW in future, a long baseline neutrino oscillation experiment with Hyper-Kamiokande as a far detector will open the possibility of measuring CP violation in the neutrino sector. Also, Hyper-Kamiokande will allow to extend nucleon decay search to τp/B(p → e+π0) > 1035yr and $\tau_p/B(p\to\bar{
u}K^+)>10^{34}~{\rm yr}$. Aiming at the realization of Hyper-Kamiokande, various R&D efforts are in progress.
132 citations
University of Wisconsin-Madison1, University of Mainz2, Institute for Advanced Study3, University of Kansas4, University of Maryland, College Park5, Université libre de Bruxelles6, Uppsala University7, Stockholm University8, University of Mons-Hainaut9, University of California, Berkeley10, Pennsylvania State University11, Vrije Universiteit Brussel12, University of California, Santa Cruz13, University of Delaware14, Southern University and A&M College15, Lawrence Berkeley National Laboratory16, Clark Atlanta University17, Imperial College London18, University of Wisconsin–River Falls19, Simón Bolívar University20, Chiba University21
TL;DR: In this paper, the conceptual design and sensitivity of the IceCube detector to predicted fluxes of neutrinos, both atmospheric and extra-terrestrial, were presented and a complete simulation of the detector design has been used to study the detector's capability to search for neutrino from sources such as active galaxies, and gamma-ray bursts.
Abstract: IceCube is a large neutrino telescope of the next generation to be constructed in the Antarctic Ice Sheet near theSouth Pole. We present the conceptual design and the sensitivity of the IceCube detector to predicted fluxes of neutrinos, both atmospheric and extra-terrestrial. A complete simulation of the detector design has been used to study the detector's capability to search for neutrinos from sources such as active galaxies, and gamma-ray bursts.
116 citations
TL;DR: In this article, the authors consider the problem of computing the nuclear matrix elements of neutrinoless double-β decay and discuss the possibility to check the results of different model calculations through their comparison with the experimental data.
101 citations
24 Oct 2003
TL;DR: In this paper, the results from the first phase of Sudbury Neutrino Observatory (SNO) were described, as well as the progress and challenges of SNO's Phase II.
Abstract: We describe here both the results from the first phase of Sudbury Neutrino Observatory (SNO), as well as the progress and challenges of SNO’s Phase II.
101 citations
TL;DR: In this article, it was shown that plasmon neutrinos are the dominant form of energy loss in model white dwarf stars down to T −eff ~ 25,000 K, depending on the stellar mass.
Abstract: We demonstrate that plasmon neutrinos are the dominant form of energy loss in model white dwarf stars down to T_eff ~ 25,000 K, depending on the stellar mass. The lower end of this range overlaps the observed temperatures for the V777 Her star (DBV) instability strip. The evolution of white dwarfs at these temperatures is driven predominantly by cooling, so this directly affects the stellar evolutionary timescale in proportion to the ratio of the neutrino energy loss to the photon energy loss. This evolutionary timescale is observable through the time rate of change of the pulsation periods. Although the unified electro-weak theory of lepton interactions that is crucial for understanding neutrino production has been well tested in the high energy regime, the approach presented here should result in an interesting low-energy test of the theory. We discuss observational strategies to achieve this goal.
98 citations
TL;DR: In this article, a review of neutrino experiments is presented, along with the results from Super-Kamiokande and other underground atmospheric neutrinos experiments, and a unified picture with νμ to ντ oscillation as the dominant mode emerges; however, certain ambiguities remain.
Abstract: ▪ Abstract The observation of muon flavor disappearance in the atmospheric neutrino flux provides compelling evidence for neutrino flavor oscillations and, by implication, for nonzero neutrino rest mass. We review recent results from Super-Kamiokande and other underground atmospheric neutrino experiments. These results, along with oscillation limits from reactor experiments, are evaluated in the context of neutrino three-state mixing. A unifying picture with νμ to ντ oscillation as the dominant mode emerges; however, certain ambiguities remain. Future directions for further experimentation are discussed.
98 citations
TL;DR: In this article, the authors studied the statistical efficiency of different methods for extracting the SN direction and identified a simple approach that is nearly optimal, yet independent of the exact SN neutrino spectra.
Abstract: A future galactic SN can be located several hours before the optical explosion through the MeV-neutrino burst, exploiting the directionality of $\ensuremath{
u}\ensuremath{-}e$ scattering in a water Cherenkov detector such as Super-Kamiokande. We study the statistical efficiency of different methods for extracting the SN direction and identify a simple approach that is nearly optimal, yet independent of the exact SN neutrino spectra. We use this method to quantify the increase in the pointing accuracy by the addition of gadolinium to water, which tags neutrons from the inverse beta decay background. We also study the dependence of the pointing accuracy on neutrino mixing scenarios and initial spectra. We find that in the ``worst case'' scenario the pointing accuracy is $8\ifmmode^\circ\else\textdegree\fi{}$ at 95% C.L. in the absence of tagging, which improves to $3\ifmmode^\circ\else\textdegree\fi{}$ with a tagging efficiency of 95%. At a megaton detector, this accuracy can be as good as $0.6\ifmmode^\circ\else\textdegree\fi{}.$ A TeV-neutrino burst is also expected to be emitted contemporaneously with the SN optical explosion, which may locate the SN to within a few tenths of a degree at a future ${\mathrm{km}}^{2}$ high-energy neutrino telescope. If the SN is not seen in the electromagnetic spectrum, locating it in the sky through neutrinos is crucial for identifying the Earth matter effects on SN neutrino oscillations.
TL;DR: In this article, the angular distribution of upward-going muons and cascade events induced by atmospheric neutrinos at the TeV energy scale, which can be performed by a kilometer-scale neutrino telescope, such as the IceCube detector, can be used to probe a large neutRino mass splitting.
TL;DR: In this article, the Earth effect was detected by using the neutrino mixing parameters at the future km 3 antarctic ice Cherenkov Neutrino Telescope (ICEBOAT) with a statistical precision of better than 1%.
Abstract: IceCube, a future km 3 antarctic ice Cherenkov neutrino telescope, is highly sensitive to a galactic supernova (SN) neutrino burst. The Cherenkov light corresponding to the total energy deposited by the SN neutrinos in the ice can be measured relative to background fluctuations with a statistical precision much better than 1%. If the SN is viewed through the Earth, the matter effect on neutrino oscillations can change the signal by more than 5%, depending on the flavour-dependent source spectra and the neutrino mixing parameters. Therefore, IceCube together with another high-statistics experiment like Hyper-Kamiokande can detect the Earth effect, an observation that would identify specific neutrino mixing scenarios that are difficult to pin down with long-baseline experiments. In particular, the normal mass hierarchy can be clearly detected if the third mixing angle is not too small, sin 2 θ13 10 −3 . The small flavour-dependent differences of the SN neutrino fluxes and spectra that are found in state-of-the-art simulations suffice for this purpose. Although the absolute calibration uncertainty at IceCube may exceed 5%, the Earth effect would typically vary by a large amount over the duration of the SN signal, obviating the need for a precise calibration. Therefore, IceCube with its unique geographic location and expected longevity can play a decisive role as a 'co-detector' to measure SN neutrino oscillations. It is also a powerful stand-alone SN detector that can verify the delayed-explosion scenario.
TL;DR: In this paper, the effect of neutrino feedback on the Mikheyev-Smirnov-Wolfenstein (MSW) conversion potential was investigated in a post-core-bounce supernova environment.
TL;DR: The Radio Ice Cherenkov Experiment at the South Pole, co-deployed with the AMANDA experiment, seeks to detect ultra-high energy electron neutrinos interacting in cold polar ice.
TL;DR: In this article, the authors investigated the flux and event rate of the supernova relic neutrino (SRN) background at the SuperKamiokande (SK) detector.
TL;DR: In this article, the effective target volumes and masses for Tau air-showers emerging from the Earth were calculated, considering both the Earth opacity and the finite size of the terrestrial atmosphere, and the resulting model independent masses for satellite experiments such as EUSO may encompass at E_nu_tau = 10^19 eV a very large volume, V= 1020 km^3.
Abstract: We estimate the rate of observable Horizontal and Upward Tau Air-Showers (HORTAUs, UPTAUS) considering both the Earth opacity and the finite size of the terrestrial atmosphere. We calculate the effective target volumes and masses for Tau air-showers emerging from the Earth. The resulting model-independent masses for satellite experiments such as EUSO may encompass at E_nu_tau = 10^19 eV a very large volume, V= 1020 km^3. Adopting simple power law neutrino fluxes, E^-2 and E^-1, calibrated to GZK-like and Z-Burst-like models, we estimate that at E= 10^19 eV nearly half a dozen horizontal shower events should be detected by EUSO in three years of data collection by the "guaranteed" GZK neutrino flux. We also find that the equivalent mass for an Earth outer layer made of rock is dominant compared to the water, contrary to simplified all-rock/all-water Earth models and previous Montecarlo simulations. Therefore we expect an enhancement of neutrino detection along continental shelves nearby the highest mountain chains, also given the better geometrical acceptance for Earth skimming neutrinos. The Auger experiment might reveal such a signature at E_nu= 10^{18} eV (with 26 events in 3 yr) towards the Andes, if the angular resolution at the horizon (both in azimuth and zenith) would reach an accuracy of nearly one degree needed to disentangle tau air showers from common UHECR. The number of events increases at lower energies; therefore we suggest an extension of the EUSO and Auger sensitivity down to (or even below) E_nu = 10^19 eV and E_nu = 10^18 eV respectively.
TL;DR: In this article, the authors examined the prospect of using lead as a supernova-neutrino detector by considering the spectrum of electrons produced, and the number of one and two neutrino events.
Abstract: We examine the prospects for using lead as a supernova-neutrino detector by considering the spectrum of electrons produced, and the number of one- and two-neutron events. We show that the electron energy spectrum from charged-current reactions could be used to extract information about the high-temperature component of the neutrino spectrum. Some degree of electron neutrino oscillation is expected in the supernova envelope. We examine the prospects for untangling the signatures of various oscillation scenarios, including, e.g., normal or inverted hierarchies, and different values for the small mixing angle ${\ensuremath{\theta}}_{13}.$
01 Jan 2003
TL;DR: Object-oriented real-time control and acquisition software is the framework for the data acquisition system of the NCD array and provides generic object-oriented software modules that can be configured and connected together at run-time to build general-purpose data acquisition applications.
Abstract: The Sudbury Neutrino Observatory (SNO) begins a new phase of operation in the autumn of 2003 with the installation of the Neutral Current Detector (NCD). This paper focuses mainly on the Object-oriented Real-time Control and Acquisition (ORCA) software that is the framework for the data acquisition system of the NCD array. Particular emphasis is given to the general purpose nature of ORCA and the manner in which it provides generic object-oriented software modules that can be configured and connected together at run-time to build general-purpose data acquisition applications. ORCA is the main graphical user interface for the NCD experiment and is used for hardware initialization, run control, data readout, and data shipping.
TL;DR: The sensitivity of the present CNGS beam to the sub-dominant νμ ↔ νe oscillations in the region indicated by the atmospheric neutrino experiments is investigated in this paper.
Abstract: The sensitivity of the present CNGS beam to the sub-dominant νμ ↔ νe oscillations in the region indicated by the atmospheric neutrino experiments is investigated. In particular, we present a revised analysis of the OPERA detector and discuss the sensitivity to θ13 of ICARUS and OPERA combined. We show that the CNGS beam optimized for ντ appearance will improve significantly (about a factor of 5) the current limit of CHOOZ and explore most of the region sin2 2θ13 (10−2).
01 Apr 2003
TL;DR: In this paper, different options for a next generation direct neutrino mass experiment with sub-eV sensitivity are discussed, and the KATRIN experiment, which will investigate the tritium β spectrum with a 1 eV resolution MAC-E-Filter, is being prepared to reach a sub eV sensitivity.
Abstract: One of the most important tasks in neutrino physics is to determine the neutrino mass scale to distinguish between hierarchical and degenerate neutrino mass models and to clarify the role of neutrinos in the early universe. The current tritium β decay experiments at Mainz and Troitsk are reaching their sensitivity limit. The synchronous measurements at Mainz and Troitsk show that the “Troitsk anomaly” is an experimental artefact. The different options for a next generation direct neutrino mass experiment with sub-eV sensitivity are discussed. The KATRIN experiment, which will investigate the tritium β spectrum with a 1 eV resolution MAC-E-Filter, is being prepared to reach a sub-eV sensitivity.
TL;DR: In this paper, the first tests of micropattern gas detectors (MPGDs) fabricated with radioclean materials and discuss the approach to assessing their sensitivity to these faint signals.
Abstract: The detection of low energy neutrinos ( 1 kg) are not sensitive to sub keV nuclear recoils like those expected from this channel. The advent of micropattern gas detectors (MPGDs), new technologies originally intended for use in high energy physics, may soon put an end to this impasse. We present first tests of MPGDs fabricated with radioclean materials and discuss the approach to assessing their sensitivity to these faint signals. Applications are reviewed, in particular their use as a safeguard against illegitimate operation of nuclear reactors. A first industrial mass production of gas electron multipliers (GEMs) is succinctly described.
TL;DR: In this paper, the effect of sterile neutrinos that are nearly degenerate with active ones on the flux of ultrahigh-energy cosmic ray neutrino at earth was investigated.
11 Apr 2003-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: NESTOR is a deep-sea water Cherenkov neutrino detector now under construction for deployment in the Mediterranean sea, at a depth of 4000 m, 14 km off the South West coast of Greece.
Abstract: NESTOR is a deep-sea water Cherenkov neutrino detector now under construction for deployment in the Mediterranean sea, at a depth of 4000 m , 14 km off the South West coast of Greece. This site provides excellent water transparency, shielding against the atmospheric muons, proximity to the shore, flat and wide sea bottom and stable geological and other environmental characteristics. The present status of the experiment and the future program are described.
28 Nov 2003
TL;DR: In this article, the early universe, supernovae, and newly born neutron stars were detected using neutrinos from different eras using the new generation of neutrino detectors.
Abstract: ▪ Abstract Even the elusive neutrinos are trapped in matter, albeit transiently, in several astrophysical circumstances. Their interactions with the ambient matter not only reveal the properties of such exotic matter, but also shed light on the fundamental properties of the neutrinos. The physical sites of interest include the early universe, supernovae, and newly born neutron stars. Detection of neutrinos from these vastly different eras using the new generation of neutrino detectors holds great promise for enhancing our understanding of neutrino-matter interactions and astrophysical phenomena.
01 Apr 2003
TL;DR: In this article, a combined analysis of the data of 92 runs of SAGE during the 12-year period January 1990 through December 2001 gives a capture rate of solar neutrinos with energy more than 233 keV of 70.9 −5.2 +5.3 (stat.) −3.7 (syst.) SNU.
Abstract: Combined analysis of the data of 92 runs of SAGE during the 12-year period January 1990 through December 2001 gives a capture rate of solar neutrinos with energy more than 233 keV of 70.9 −5.2 +5.3 (stat.) −3.2 +3.7 (syst.) SNU. This represents only 55% of the predicted standard solar model rate of ∼130 SNU. The results of individual runs as well as the results of combined analysis of all runs during yearly, monthly, and bimonthly periods are presented. No compelling evidence for temporal variations is observed. By an analysis of the SAGE results combined with those from all other solar neutrino experiments, we make the first estimate of the electron neutrino pp flux that reaches the Earth to be (4.6 ± 1.2) x 10 10 /(cm 2 s). Assuming that neutrinos oscillate to active flavors the pp neutrino flux emitted in the solar fusion reaction is approximately (7.6 ± 2.0) x 10 10 /(cm 2 s), in agreement with the standard solar model calculation of (5.95 ± 0.06) x 10 10 /(cm 2 s).
TL;DR: In this paper, the authors combine KamLAND data with solar neutrino data and show that the LMA solution is the only viable oscillation solution to the solar NE problem at the 4.4 σ C.L.
Seoul National University1, University of Tokyo2, Boston University3, Harvard University4, Brookhaven National Laboratory5, University of California, Irvine6, California State University, Dominguez Hills7, Chonnam National University8, George Mason University9, Gifu University10, University of Chicago11, Kobe University12, Kyoto University13, Los Alamos National Laboratory14, Louisiana State University15, University of Maryland, College Park16, Massachusetts Institute of Technology17, University of Minnesota18, Stony Brook University19, University of Utah20, Nagoya University21
TL;DR: A search for periodic modulations of the solar neutrino flux was performed using the Super-Kamiokande-I data taken from May 31st, 1996 to July 15th, 2001 as mentioned in this paper.
Abstract: A search for periodic modulations of the solar neutrino flux was performed using the Super-Kamiokande-I data taken from May 31st, 1996 to July 15th, 2001. The detector's capability of measuring the exact time of events, combined with a relatively high yield of solar neutrino events, allows a search for short-time variations in the observed flux. We employed the Lomb test to look for periodic modulations of the observed solar neutrino flux. The obtained periodogram is consistent with statistical fluctuation and no significant periodicity was found.
TL;DR: In this article, the role of neutrino-nucleus interactions in core-collapse supernovae is explored and open questions are discussed, in addition implications of neutrinuclear mass and mixings in such environments are summarized.
Abstract: In this brief review we explore the role of neutrino-nucleus interactions in core-collapse supernovae and discuss open questions. In addition implications of neutrino mass and mixings in such environments are summarized.
University of Mainz1, University of Delaware2, University of California, Berkeley3, University of Wuppertal4, Université libre de Bruxelles5, Uppsala University6, Stockholm University7, University of Mons8, University of Wisconsin-Madison9, Pennsylvania State University10, Vrije Universiteit Brussel11, Lawrence Berkeley National Laboratory12, University of Wisconsin–River Falls13, Simón Bolívar University14
TL;DR: The AMANDA-B10 and-II detector as mentioned in this paper is a multipurpose detector with significant physics and astrophysics reach, and it has been used to detect neutrinos from a variety of sources, including point sources, gamma-ray bursters and diffuse sources.
Abstract: We show new results from both the older and newer incarnations of AMANDA (AMANDA-B10 and AMANDA-II, respectively). These results demonstrate that AMANDA is a functioning, multipurpose detector with significant physics and astrophysics reach. They include a new higher-statistics measurement of the atmospheric muon neutrino flux and preliminary results from searches for a variety of sources of ultrahigh energy neutrinos: generic point sources, gamma-ray bursters and diffuse sources producing muons in the detector, and diffuse sources producing electromagnetic or hadronic showers in or near the detector.