Search

The IceCube Neutrino Observatory, located in the deep clear ice below the surface of the geographic South Pole, has recently reported the discovery of an astrophysical neutrino flux. In order to do neutrino astronomy, it is essential to have a large sample of well-reconstructed, astrophysical neutrinos, with as little contamination from atmospheric backgrounds as possible. The ability to veto air showers at ∼ 100 TeV could efficiently enhance the sample of astrophysical neutrinos. This contribution describes the feasibility of using an array of small scale, wide field-of-view and cost effective Imaging Atmospheric Cherenkov Telescopes to veto air showers for neutrino astronomy.

It is well known that the neutrino sector can provide a dark matter candidate in the form of a light sterile neutrino. This note discusses a framework that naturally leads to light (keV-GeV) sterile neutrino dark matter produced via the freeze-in mechanism: a modified, low energy seesaw with the right-handed neutrinos charged under a new symmetry broken by a PeV scale vacuum expectation value. This framework can accommodate the recently observed 3.5 keV X-ray line, while a straightforward extension, using the new symmetry and the PeV energy scale, can explain the PeV energy neutrino events at IceCube. Together, these can therefore be taken as hints of the existence of a PeV scale neutrino sector.

We present preliminary results on the measurement of neutrino oscillations with three years of data of the completed IceCube Neutrino Observatory. With an energy threshold of about 10 GeV, the detector is sensitive to the disappearance of atmospheric muon neutrinos. The effect is measured using a sample of high-quality muon neutrino events that interact in DeepCore, a region of denser instrumentation. In a livetime of 953 days, 5174 events are found with expectation of 6980 without oscillations. The energy−zenith angle distribution of the events is analyzed yielding the best-fit oscillation parameters sin2 (θ23) = 0.51 ± 0.09 and Δm322=2.68−0.18+0.19×10−3eV2 (normal mass hierarchy assumed). The result achieves a precision similar to that of the Super-Kamiokande experiment, which also analyzes atmospheric neutrinos but at lower energies.

Ultra-high energy (UHE) neutrino astronomy constitutes a new window of observation onto the UHE universe. The detection and characterization of astrophysical neutrinos at the highest energies (E> 1018 eV) would reveal the sources of high-energy cosmic rays, the highest energy particles ever seen, and would constrain the evolution of such sources over time. UHE neutrino astrophysics also allows us to probe weak interaction couplings at energies much greater than those available at particle colliders. One promising way of detecting the highest energy neutrinos is through the radio emission created when they interact in a large volume of dielectric, such as ice. Here I discuss current results and future efforts to instrument large volumes of detector material with radio antennas to detect, point back, and characterize the energy of UHE astrophysical neutrinos.

Neutrino oscillations, first measured in 1998 via atmospheric neutrinos, have provided the only current direct evidence for physics beyond the Standard Model of Elementary Particles. The full neutrino mixing, described by six parameters, has been measured in the last decade with the exception of the charge-parity phase and the ordering of the mass eigenstates (the neutrino mass hierarchy – NMH). A relatively large mixing-angle between the first and third mass eigenstates has opened the possibility of measuring the mass hierarchy via atmospheric neutrinos using very large volume detectors. A leading proposal to perform this measurement is the future low-energy extension to the IceCube–DeepCore detector, called PINGU (the Precision IceCube Next Generation Upgrade). By increasing the photocathode density in the DeepCore region, it is possible to lower the energy threshold in the fiducial volume to the region that is affected by the MSW [1, 2], and thus permits extraction of the hierarchy. Here we discuss the...

Several anomalies coming from neutrino experiments may be pointing towards new physics: these hints suggest the existence of one (or more) sterile neutrinos. We discuss some of the experiments proposed to verify (or disproof) this hypothesis by using an intense radioactive source in proximity of large neutrino detectors.

The theory and phenomenology of supernova neutrinos is reviewed, with focus on the most recent advancements on the neutrino flux predicted by supernova numerical models, on neutrino oscillations inside the star and in the Earth, and on the physics of the diffuse supernova neutrino background. Future directions of research are briefly summarized.

In late 2012 the US Department of Energy gave approval for the first phase of the Long-Baseline Neutrino Experiment (LBNE) that will conduct a broad scientific program including neutrino oscillations, neutrino scattering physics, search for baryon violation, supernova burst neutrinos and other related astrophysical phenomena. The project is now being reformulated as an international facility hosted by the United States. The facility will consist of an intense neutrino beam produced at Fermi National Accelerator Laboratory (Fermilab), a highly capable set of neutrino detectors on the Fermilab campus, and a large underground liquid argon time projection chamber at Sanford Underground Research Facility (SURF) in South Dakota 1300 km from Fermilab. With an intense beam and massive far detector, the experimental program at the facility will make detailed studies of neutrino oscillations, including measurements of the neutrino mass hierarchy and Charge-Parity symmetry violation, by measuring neutrino and anti-neutrino mixing separately. At the near site, the high-statistics neutrino scattering data will allow for many cross section measurements and precision tests of the Standard Model. This presentation will describe the configuration developed by the LBNE collaboration, the broad physics program, and the status of the formation of the international facility.

The IceCube detector at the South Pole is the world’s largest neutrino telescope, instrumenting a cubic kilometre of deep clear ice. Completed in late 2010, the detector has recorded the arrival directions and energies of tens of thousands of neutrinos – mostly those produced when cosmic rays collide with the Earth’s atmosphere. Here, we report on the first observation of high-energy neutrinos from beyond the Earth’s atmosphere, identified using a novel method to strongly suppress atmospheric neutrinos coming downward into the detector from the southern sky, leaving a sample of neutrinos highly likely to be of astrophysical origin.

The latest results from the ANTARES Neutrino Telescope are reported. Limits on a high energy neutrino diffuse flux have been set using for the first time both muon–track and showering events. The results for point sources obtained by ANTARES are also shown. These are the most stringent limits for the southern sky for neutrino energies below 100 TeV. Constraints on the nature of the cluster of neutrino events near the Galactic Centre observed by IceCube are also reported. In particular, ANTARES data excludes a single point–like neutrino source as the origin of this cluster. Looking for neutrinos coming from the Sun or the centre of the Galaxy, very competitive limits are set by the ANTARES data to the flux of neutrinos produced by self-annihilation of weakly interacting massive particles.

We present results from the MINERνA experiment for neutrino-nucleus scattering in the few-GeV energy region. These measurements cover a range of processes that must be modeled correctly in neutrino oscillation experiments, and in which recent results from other experiments have suggested deficiencies in the models currently used.

I will discuss several different aspects of neutrino physics and astrophysics, including neutrino oscillations and high energy neutrinos from astrophysical sources. I will review the present status of experimental results on these topics and discuss prospects for future measurements and discoveries.

In this study we investigate the discovery capability of a Very Large Volume Neutrino Telescope to Galactic extended sources. We focus on the brightest HESS gamma rays sources which are considered also as very high energy neutrino emitters. We use the unbinned method taking into account both the spatial and the energy distribution of high energy neutrinos and we investigate parts of the Galactic plane where nearby potential neutrino emitters form neutrino source clusters. Neutrino source clusters as well as isolated neutrino sources are combined to estimate the observation period for 5 sigma discovery of neutrino signals from these objects.

We investigate the prospects for discovery and discrimination of dark matter annihilation into primary neutrinos from other final states at IceCube/DeepCore. By taking detector considerations into account, we perform a fit to obtain sensitivity limits for the primary neutrino final states from annihilation of dark matter particles gravitationally captured inside the Sun. We show that for dark matter in the 50 GeV–1 TeV mass range, primary neutrinos can be distinguished from other final states at a statistically significant level with multi-year data from IceCube/DeepCore.

The ANTARES detector, located in the deep sea 40 km off the French coast, is the largest neutrino telescope in the northern hemisphere. It consists of an array of 885 photomultipliers detecting the Cherenkov light induced by charged leptons created in neutrino interactions in and around the detector. The main goal of ANTARES is to search for astrophysical neutrinos in the TeV-PeV range. This comprises searches for a diffuse cosmic neutrino flux and for fluxes from possible galactic and extragalactic sources of neutrinos. The search program also includes multi-messenger analyses based on time and/or space coincidences with other cosmic probes. The ANTARES detector is sensitive to a wide range of other phenomena, from atmospheric neutrino oscillations to dark matter annihilation or potential exotics such as nuclearites and magnetic monopoles.

Determination of the neutrino mass hierarchy (NMH) is among the most fundamental questions in particle physics. Recent measurements of 1) a large mixing angle between the first and the third neutrino mass eigenstates and 2) the first observation of atmospheric neutrino oscillations at tens of GeV with neutrino telescopes, open the intriguing new possibility to exploit matter effects in neutrino oscillation to determine the neutrino mass hierarchy. A further extension of IceCube/DeepCore called PINGU (Precision IceCube Next Generation Upgrade) has been recently envisioned with the ultimate goal to measure neutrino mass hierarchy. PINGU would consist of additional IceCube-like strings of detectors deployed in the deepest and cleanest ice in the center of IceCube. More densely deployed instrumentation would provide a threshold substantially below 10 GeV and enhance the sensitivity to the mass hierarchy signal in atmospheric neutrinos. Here we discuss an estimate of the PINGU sensitivity to the mass hierarchy determined using an approximation with an Asimov dataset and an oscillation parameter fit.

IceCube, the world's largest high-energy neutrino observatory, built at the South Pole, recently reported evidence of an astrophysical neutrino flux extending to PeV energies in the Southern Hemisphere. This observation raises the question of how the sensitivity in this energy range could be further increased. In the down-going sector, in IceCube's case the Southern Hemisphere, backgrounds from atmospheric muons and neutrinos pose a challenge to the identification of an astrophysical neutrino flux. The IceCube analysis, that led to the evidence for astrophysical neutrinos, is based on an in-ice veto strategy for background rejection. One possibility available to IceCube is the concept of an extended surface detector, IceVeto, which could allow the rejection of a large fraction of atmospheric backgrounds, primarily for muons from cosmic ray (CR) air showers as well as from neutrinos in the same air showers. Building on the experience of IceTop/IceCube, possibly the most cost-effective and sensitive way to build IceVeto is as an extension of the IceTop detector, with simple photomultiplier based detector modules for CR air shower detection. Initial simulations and estimates indicate that such a veto detector will significantly increase the sensitivity to an astrophysical flux of νμ induced muon tracks in the Southern Hemisphere compared to current analyses. Here we present the motivation and capabilities based on initial simulations. Conceptual ideas for a simplified surface array will be discussed briefly.

The IceCube neutrino observatory built in the antarctic ice offers unique opportunities in studying high energy neutrino emission from Galactic and extragalactic sources. Detecting such neutrino emission could give valuable information about the origin of cosmic rays. Recently, first evidence for a diffuse astrophysical neutrino signal in the PeV range was found with IceCube. There is no clear point source signal yet, and advanced analysis methods are being developed in order to improve the sensitivity to point sources and resolve the diffuse signal into point sources. Other searches like a energy-dependent likelihood scan were already performed on IceCube data. In this paper, we report a complementary search for multiple neutrino point sources from three years of IceCube data, performing an autocorrelation test on the full sky. This analysis is aiming for various faint sources at unknown positions and energy spectra in the sky. The result obtained from this search is consistant with a background-only case and shows an underfluctuation. Here, we present limits using the ansatz of the small-scale anisotropy search.

The IceCube neutrino telescope was augmented with the DeepCore infill array, completed in the 2010/11 austral summer, to enhance its response to neutrinos below 100 GeV. At these energies, neutrino oscillation effects are visible in the flux of atmospheric neutrinos traversing path lengths comparable to the Earth's diameter. Initial measurements of muon neutrino disappearance parameters using data from DeepCore are presented, as well as an estimate of potential future precision. In addition, plans for a Precision IceCube Next Generation Upgrade (PINGU), which could permit determination of the neutrino mass hierarchy within the coming decade, are discussed.

The cubic-kilometer sized IceCube neutrino observatory, constructed in the glacial ice at the South Pole, offers new opportunities for neutrino physics to reach lower neutrino energies with its in-fill array "DeepCore". A set of analysis techniques where the outer layers of IceCube are used as a veto makes it possible to reject atmospheric muons and thereby allows low-energy neutrino searches to be performed above the horizon. With these techniques the Galactic Center, an important target in searches for self-annihilating dark matter, becomes accessible for IceCube. In this contribution, we present the status of the Galactic Center dark matter analysis, using more than 10 months of data taken with the 79-string configuration of IceCube-DeepCore, as well as the new veto techniques used in the analysis.

The existence of ultra-high energy (UHE) cosmic rays (CRs) with energies up to 100 EeV is a strong motivation for neutrino astronomy at the EeV energy scale. It seems unavoidable that UHE CRs undergo hadronic interactions with radiation backgrounds and ambient matter prior to their arrival at Earth. These interactions result in a flux of secondary neutrinos and γ-rays with energies up to a few percent of the initial CR energy. So far, no high-energy neutrino source could be unambiguously identified. We will review the various indirect neutrino limits that arise from the cosmic connection of UHE CRs, γ-rays and neutrinos. At the EeV energy scale the diffuse flux of cosmogenic neutrinos associated with the propagation of ultra-high energy cosmic rays in the cosmic radiation background seems to be the most promising candidate for a future detection. We will discuss its model dependence w.r.t. nuclear composition and evolution of the sources.

We discuss the potential of a neutrino detector based on liquid scintilator which could be constructed at the ANDES underground laboratory for the observations of neutrinos coming from a galactic supernova and decay of radioactive elements in the Earth interior.

Experiments with solar, atmospheric, reactor and accelerator neutrinos have produced data of great scientific relevance, providing compelling evidence for neutrino oscillations caused by nonzero neutrino masses and mixing. The observation of the neutrino oscillation pattern is indeed amongst the major discoveries of the last two decades and demands significant revision of the Standard Model. Many important questions still remain unanswered: What is the hierarchy of the neutrino masses? Are neutrinos their own antiparticles? What is their mass scale? Are there more than 3 neutrino species? In this paper recent developments in the current Neutrino Oscillation studies are reviewed, from electron antineutrino and muon neutrino disappearance experiments to tau and electron neutrino appearance experiments, with an eye to the future neutrino oscillation experiments and facilities. Neutrino oscillation physics is in fact entering an exciting period, with several experiments under construction, or on the horizon, addressing the discovery of the neutrino mass hierarchy, to the study of CP violation in the leptonic sector and possibly to the observation of new unexpected neutrino phenomena.

We investigate the prospects for distinguishing dark matter annihilation channels using the neutrino flux from gravitationally captured dark matter particles annihilating inside the sun. We show that distinguishing primary neutrinos from the gauge boson/charged lepton final states and determining their flavor may be achieved using multi-year data from a detector with the same capability as the IceCube/DeepCore array.

This paper is a brief historical review of the quest to find neutrinos of extraterrestrial origin. In the context of the Victor Hess centenary, it is interesting to consider how the development of detectors for neutrinos from space relates to developments in cosmic-ray and particle physics over the same time span.

I consider the possibility that some exotic neutrino property is responsible for reducing the muon neutrino flux at high energies from distant sources; specifically, (i) neutrino decay and (ii) neutrinos being pseudo-Dirac particles. This would provide a mechanism for the lack of high energy muon events in the Icecube detector.

Neutrino production and oscillation physics can be studied by utilizing the very high flux of atmospheric neutrinos observed with IceCube. In a Cherenkov medium such as ice, atmospheric muon neutrino interactions create tracks while cascades (showers) are produced by atmospheric electron neutrinos and by neutral current interactions of all flavors. We present the first detection of atmospheric neutrino-induced cascades at energies between 30 GeV and 10 TeV using the DeepCore array of the IceCube detector. Using 281 days of data, 1029 events are observed with 59% predicted to be cascades.

The ANTARES neutrino telescope is currently the largest operating water Cherenkov detector and the largest neutrino detector in the Northern Hemisphere. The detector array consists of 12 detector lines holding a total of 885 Optical Modules and is located in the Mediterranean Sea at a depth of about 2500 m. Its scientific target is the detection of ultra-high energy cosmic neutrinos through measurement of Cherenkov radiation from neutrino-induced charged leptons. ANTARES is thus optimized for the detection of high-energy muons which are produced in the vicinity of the detection volume. Since the completion of the detector in 2008, analysis of the ANTARES data is continuously improving. Its primary goal is the identification of neutrinos from cosmic accelerators as predicted by hadronic interaction models, and the measurement of the diffuse neutrino flux. Further investigation covers the search for neutrinos from dark matter annihilation and the measurement of neutrino oscillations. The various prospects and current status of the analysis will be presented.

This is an overview of the current status of neutrino oscillation physics, including atmospheric, solar, reactor and accelerator neutrino experiments. After summarizing our present understanding of all data, I discuss the open questions and how they might be addressed in the future. I also discuss how neutrinos can be used to learn about new physics and astrophysics.

High-energy neutrinos from cosmic origin appear to be ideal probes for long-distance astronomy and may provide insight into cosmic particle acceleration mechanisms. The ANTARES deep-sea neutrino telescope, fully operational since May 2008, aims at the detection of upgoing muon tracks caused by high energy neutrinos having passed through the Earth. Stringent limits have been set on the sensitivity to neutrino point sources and a diffuse neutrino flux for the Southern sky.

The KM3NeT Consortium is currently carrying on a research and development activity to build a cubic kilometerscale neutrino telescope in the deep Mediterranean Sea. The KM3NeT Consortium follows on from the NEMO and NESTOR pilot projects, which have produced several prototypes and the ANTARES collaboration, which has built and is operating a 0.1 cubic kilometer volume deep-sea neutrino telescope. The KM3NeT Mediterranean neutrino telescope will complement the Antarctic Icecube observatory, allowing the complete survey of the sky using neutrinos as a probe. The main physics goals of KM3NeT include the detection of neutrinos from astrophysical sources such as active galactic nuclei, supernova remnants and γ-ray bursts as well as the search for new physics, such as neutrino signals from neutralino annihilation. To achieve the best performance, an extensive optimisation process is underway, looking for the best geometrical configuration of the detector for maximum sensitivity, and evaluating the most reliable...

The recently completed IceCube observatory is a 1 km3 neutrino detector with powerful capabilities to explore the Universe. Its primary goal is to observe cosmic neutrinos with energies in the TeV to PeV range. IceCube has been collecting data since the deployment of the first string in 2005. We discuss the IceCube physics program and selected latest results.

The neutrino spectra from a future galactic core collapse supernova could reveal information on the neutrino mixing pattern, especially on θ13 and the mass hierarchy. I briefly outline our current understanding of neutrino flavor conversions inside a supernova, and point out possible signatures of various neutrino mixing scenarios that the neutrino detectors should look for. Supernova neutrinos provide a probe for θ13 and mass hierarchy that is complementary to, and sometimes even better than, the current and proposed terrestrial neutrino oscillation experiments.

LENA (Low Energy Neutrino Astronomy) is a proposed next generation liquid‐scintillator detector with about 50 kt target mass. Besides the detection of solar neutrinos, geoneutrinos, supernova neutrinos and the search for the proton decay, LENA could also be used as the far detector of a next generation neutrino beam. The present contribution outlines the status of the Monte Carlo studies towards the reconstruction of GeV neutrinos in LENA. Both the tracking capabilities at a few hundred MeV, most interesting for a beta beam, and above 1 GeV for a superbeam experiment are presented.

Forty years ago it was recognized that the detection of high energy (≳TeV) neutrinos from astronomical sources would require the construction of a device with 1 gigaton (or 1 cubic kilometer of ice) of target material. This idea is now becoming a reality at the South Pole with the construction of IceCube. Detection of extraterrestrial high energy neutrinos will open new avenues in astrophysics and neutrino physics. A positive observation of neutrinos in coincidence with a GRB would identify these objects as one the source of the highest energy cosmic rays and would provide invaluable information about the processes responsible for GRBs.In this paper I summarize the results from searches for neutrinos from GRBs with IceCube and its predecessor, AMANDA. I review the status of the construction and operation of IceCube. Finally, I outline future directions for IceCube, in particular in searches of neutrinos from GRBs reported by Fermi.

Many experiments have contributed to the current picture of neutrino oscillations. However, some fundamental pieces of the neutrino puzzle remain undiscovered. The last unknown mixing angle of the neutrino matrix, θ13, the neutrino mass hierarchy and the CP violation parameter have yet to be measured. To further our exploration in the neutrino sector we need detectors of unprecedented size and an intense neutrino beam over a very long distance. The Long‐Baseline Neutrino Experiment (LBNE) must accomplish this goal.

Neutrinos are very special particles, have only weak interactions, except gravity, and are produced in very different processes in Nuclear and Particle Physics. Neutrinos are, also, messengers from astrophysical objects, as well as relics from Early Universe. Therefore, its can give us information on processes happening in the Universe, during its evolution, which cannot be studied otherwise. The underground instrumentation including a variety of large and very large detectors, thanks to technical breakthroughs, have achieved new fundamental results like the solution of the solar neutrino puzzle and the evidence for Physics beyond the Standard Model of elementary interactions in the neutrino sector with non‐vanishing neutrino masses and lepton flavour violation.Two of the LAGUNA (Large Apparatus studying Grand Unification and Neutrino Astrophysics) detectors, namely: GLACIER (Giant Liquid Argon Charge Imaging ExpeRiment) [1] and LENA (Low Energy Neutrino Astrophysics) [2] could be emplaced in “Unirea” salt mine from Slanic‐Prahova, Romania. A detailed analysis of the conditions and advantages is necessary. A few results have been presented previously [3]. In the present work, we propose to generate events and compute the cross sections for interactions between neutrino and Argon‐40, to estimate possible detection performances and event types. For doing this, we use the code GENIE (G_enerates E_vents for N_eutrino I_nteraction E_xperiments) [4]. GENIE Code is an Object‐Oriented Neutrino MC Generator supported and developed by an international collaboration of neutrino interaction experts.