Probing particle physics with IceCube Ahlers, Markus; Helbing, Klaus; Pérez de los Heros, Carlos
The European physical journal. C, Particles and fields,
11/2018, Volume:
78, Issue:
11
Journal Article
Peer reviewed
Open access
The IceCube observatory located at the South Pole is a cubic-kilometre optical Cherenkov telescope primarily designed for the detection of high-energy astrophysical neutrinos. IceCube became fully ...operational in 2010, after a seven-year construction phase, and reached a milestone in 2013 by the first observation of cosmic neutrinos in the TeV–PeV energy range. This observation does not only mark an important breakthrough in neutrino astronomy, but it also provides a new probe of particle physics related to neutrino production, mixing, and interaction. In this review we give an overview of the various possibilities how IceCube can address fundamental questions related to the phenomena of neutrino oscillations and interactions, the origin of dark matter, and the existence of exotic relic particles, like monopoles. We will summarize recent results and highlight future avenues.
The Wavelength-Shifting Optical Module Bastian-Querner, Benjamin; Binn, Lucas S; Böser, Sebastian ...
Sensors (Basel, Switzerland),
02/2022, Volume:
22, Issue:
4
Journal Article
Peer reviewed
Open access
The Wavelength-shifting Optical Module (WOM) is a novel photosensor concept for the instrumentation of large detector volumes with single-photon sensitivity. The key objective is to improve the ...signal-to-noise ratio, which is achieved by decoupling the photosensitive area of a sensor from the cathode area of its photomultiplier tube (PMT). The WOM consists of a transparent tube with two PMTs attached to its ends. The tube is coated with wavelength-shifting paint that absorbs ultraviolet photons with nearly 100% efficiency. Depending on the environment, e.g., air (ice), up to 73% (41%) of the subsequently emitted optical photons can be captured by total internal reflection and propagate towards the PMTs, where they are recorded. The optical properties of the paint, the geometry of the tube, and the coupling of the tube to the PMTs have been optimized for maximal sensitivity based on theoretical derivations and experimental evaluations. Prototypes were built to demonstrate the technique and to develop a reproducible construction process. Important measurable characteristics of the WOM are the wavelength-dependent effective area, the transit time spread of detected photons, and the signal-to-noise ratio. The WOM outperforms bare PMTs, especially with respect to the low signal-to-noise ratio with an increase of a factor up to 8.9 in air (5.2 in ice). Since the gain in sensitivity is mostly in the UV regime, the WOM is an ideal sensor for Cherenkov and scintillation detectors.
Many instruments for astroparticle physics are primarily geared towards multi-messenger astrophysics, to study the origin of cosmic rays and to understand high-energy astrophysical processes. Since ...these instruments observe the Universe at extreme energies and in kinematic ranges not accessible at accelerators these experiments provide also unique and complementary opportunities to search for particles and physics beyond the standard model of particle physics. In particular, the reach of IceCube, Fermi and KATRIN to search for and constrain Dark Matter, Axions, heavy Big Bang relics, sterile neutrinos and Lorentz invariance violation will be discussed. The contents of this article are based on material presented at the Humboldt-Kolleg 'Clues to a mysterious Universe-exploring the interface of particle, gravity and quantum physics' in June 2022. This article is part of the theme issue 'The particle-gravity frontier'.
The Gerasimov–Drell–Hearn sum rule Helbing, Klaus
Progress in particle and nuclear physics,
10/2006, Volume:
57, Issue:
2
Journal Article
Peer reviewed
Open access
Display omitted
Sum rules measurements involving the spin structure of the nucleon like those due to Bjorken, Ellis and Jaffe and the one due to Gerasimov, Drell and Hearn allow us to study the ...structure of strong interactions. At long distance scales in the confinement regime the Gerasimov–Drell–Hearn (GDH) sum rule (Eq.
(1)) connects static properties of the nucleon–like the anomalous magnetic moment and the nucleon mass–with the difference of spin dependent doubly polarized total absorption cross sections of real photons. Hence, the full spin-dependent excitation spectrum of the nucleon is being related to its static properties. The sum rule has not been investigated experimentally until recently. Now, for the first time this fundamental sum rule is verified by the GDH-Collaboration with circularly polarized real photons and longitudinally polarized nucleons at the two accelerators
Elsa and
Mami. The investigation of the response of the proton as well as of the neutron allows us to perform an isospin decomposition. Further investigations with real photons are scheduled at
Slac,
JLab,
Spring-8,
Legs and
Graal. The integral (sum) of the GDH sum rule can be generalized to the case of virtual photons. This allows us to establish a
Q
2
dependency and to study the transition to the perturbative regime of QCD. Ultimately, the GDH sum rule can be related to the Bjorken and the Ellis–Jaffe sum rule. This transition is the subject of several experiments e.g. at
JLab for the resonance region and of the
Hermes experiment at
Desy for higher
Q
2
.
This contribution covers the status of theory concerning the GDH sum rule as well as the experimental approaches and their results for the absorption of real and virtual photons. We point out that the so-called No-Subtraction hypothesis, often considered the weakest part of the derivation of the GDH sum rule, in fact follows from unitarity and does not impair the fundamental character of the GDH sum rule. The experimental data verify the GDH sum rule for the proton at the level of 8% including the systematic uncertainties from extrapolations to unmeasured energy regions. For the GDH sum rule on the neutron and the isovector case we find unexpected contributions at photon energies above 1 GeV.
The polar regions of Mars as well as the ice-covered moons such as Saturn's Enceladus and Jupiter's Europa have emerged as significant targets for ongoing and future space missions focused on ...investigating potentially habitable celestial bodies within our solar system. A key objective of these missions is to explore subglacial water reservoirs lying beneath the ice crusts of moons, such as Europa. The utilization of melting probes shows immense promise for achieving this goal. However, in addition to the capability to melt through the ice body, such a probe must also be able to identify the ice-water interface as well as obstacles in its path, such as cavities or meteoric rocks. To address these challenges, we present a forefield reconnaissance system (FRS) featuring a hybrid sensing approach that combines radar and sonar both integrated into the tip of a melting probe. Furthermore, the system includes an in situ permittivity sensor to ensure accurate radar range assignment and to gather scientific data about the ice body. The system has been integrated into a demonstrator melting probe and tested in a terrestrial analog scenario. Measurements at the Jungfraufirn in Switzerland confirm the potential of the developed system.
The Karlsruhe Tritium Neutrino (KATRIN) experiment aims at measuring the effective electron neutrino mass with a sensitivity of 0.2 eV/c2, i.e., improving on previous measurements by an order of ...magnitude. Neutrino mass data taking with KATRIN commenced in early 2019, and after only a few weeks of data recording, analysis of these data showed the success of KATRIN, improving on the known neutrino mass limit by a factor of about two. This success very much could be ascribed to the fact that most of the system components met, or even surpassed, the required specifications during long-term operation. Here, we report on the performance of the laser Raman (LARA) monitoring system which provides continuous high-precision information on the gas composition injected into the experiment’s windowless gaseous tritium source (WGTS), specifically on its isotopic purity of tritium—one of the key parameters required in the derivation of the electron neutrino mass. The concentrations cx for all six hydrogen isotopologues were monitored simultaneously, with a measurement precision for individual components of the order 10−3 or better throughout the complete KATRIN data taking campaigns to date. From these, the tritium purity, εT, is derived with precision of <10−3 and trueness of <3 × 10−3, being within and surpassing the actual requirements for KATRIN, respectively.
The Saturnian moon Enceladus with its extensive water bodies underneath a thick ice sheet cover is a potential candidate for extraterrestrial life. Direct exploration of such extraterrestrial aquatic ...ecosystems requires advanced access and sampling technologies with a high level of autonomy. A new technological approach has been developed as part of the collaborative research project Enceladus Explorer (EnEx). The concept is based upon a minimally invasive melting probe called the IceMole. The force-regulated, heater-controlled IceMole is able to travel along a curved trajectory as well as upwards. Hence, it allows maneuvers which may be necessary for obstacle avoidance or target selection. Maneuverability, however, necessitates a sophisticated on-board navigation system capable of autonomous operations. The development of such a navigational system has been the focal part of the EnEx project. The original IceMole has been further developed to include relative positioning based on in-ice attitude determination, acoustic positioning, ultrasonic obstacle and target detection integrated through a high-level sensor fusion. This paper describes the EnEx technology and discusses implications for an actual extraterrestrial mission concept.
•The IceMole concept allows oblique melting trajectories and changing the melting direction.•Trilateration of acoustic signals yields the probe's absolute in-ice position.•Combined inertial and magnetometer data allow to track relative changes in attitude and position.•Acoustic reconnaissance provides information about the ice structure in the probe's fore-field.•Multi-sensor fusion combines all available data and provides decision support for the operator.
Many instruments for astroparticle physics are primarily geared towards multi-messenger astrophysics, to study the origin of cosmic rays (CR) and to understand high-energy astrophysical processes. ...Since these instruments observe the Universe at extreme energies and in kinematic ranges not accessible at accelerators these experiments provide also unique and complementary opportunities to search for particles and physics beyond the standard model of particle physics. In particular, the reach of IceCube, Fermi and KATRIN to search for and constrain Dark Matter, Axions, heavy Big Bang relics, sterile neutrinos and Lorentz Invariance Violation (LIV) will be discussed. The contents of this article are based on material presented at the Humboldt-Kolleg "Clues to a mysterious Universe - exploring the interface of particle, gravity and quantum physics" in June 2022.
Abstract
The Enceladus Explorer project is a preparatory study for a future space mission to Saturn’s moon, Enceladus. Its ultimate goal is to probe liquid-water pockets below the ice surface of ...Enceladus for signatures of life. A probe could be based on the IceMole concept, which melts curved trajectories through the ice. In the Enceladus Explorer project, a specialized IceMole probe for a terrestrial test scenario is in development. The goal of this exploratory study is to probe water from a liquid crevasse close to Blood Falls at Taylor Glacier, Antarctica. To navigate such a probe it is essential to be able to determine its position and monitor its trajectory. Part of the navigation system is the in-ice acoustic positioning system. For this, the head of the IceMole is equipped with acoustic sensors, which receive signals from synchronized acoustic emitters situated at the ice surface. Based on the measured propagation times, the speed of sound in ice and the positions of the emitters at the surface, the position of the IceMole can be determined by trilateration techniques. Here we present the developed acoustic positioning system, which is designed to track the in-ice melting probe up to distances of 100 m in glacier ice. Results from full-system tests in water and a first field test on Morteratschgletscher, Switzerland, are discussed.
A radio air shower detector as an extension for IceCube and IceTop Auffenberg, Jan; Besson, Dave; Gaisser, Tom ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
06/2009, Volume:
604, Issue:
1
Journal Article
Peer reviewed
Open access
The IceCube neutrino detector is being built into the Antarctic ice sheet at the South Pole to measure high energy neutrinos. For this, 4800 PMTs are being deployed at depths between 1450 and 2450
m ...into the ice to identify neutrino induced charged particles like muons. IceTop is a surface air shower detector consisting of 160 ice Cherenkov tanks located on top of IceCube. A radio air shower detector is designed to extend IceTop and increase significantly the sensitivity at higher shower energies and for inclined showers. Furthermore, composition studies would be improved with this three component detector comprising IceCube, IceTop and Radio. In this scenario IceCube detects the muonic component, IceTop the charged particles at the surface and radio measures the longitudinal development of the air shower. Furthermore, high energy air showers generate the muonic background for the extra high energy (EHE) neutrino detection in IceCube. For this, a radio extension of IceCube is not only an air shower detector, but also works as a veto to reduce this background. Radio background studies and simulations of the expected radio signals from air showers lead to an estimation of the radio detector efficiency. The requirements necessary for a veto detector are outlined in this work.
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