Conveners
Neutrinos
- Carsten Rott (Sungkyunkwan University)
Neutrinos
- Markus Ahlers (Niels Bohr International Academy, Niels Bohr Institute)
Neutrinos
- Markus Ahlers (Niels Bohr International Academy, Niels Bohr Institute)
Neutrinos
- Sergio Palomares-Ruiz (IFIC-Valencia)
Neutrinos
- Ke Fang (University of Maryland)
Neutrinos
- Amy Connolly (Ohio State University)
Neutrinos
- Carl Pfendner
The next Galactic supernova (SN) will probably occur while current or next generation neutrino experiments are online. It is crucial to have correct understanding of the basic characteristics of the expected neutrino signals. The nominal expectation of the duration of the neutrino signal is ~ 10 s; this expectation guided both theoretical and experimental effort. We simulate SN neutrino...
Supernova neutrinos can experience “fast” self-induced flavor conversions almost immediately above the core, with important implications for the explosion mechanism and nucleosynthesis. Very recently, a novel method has been proposed to investigate these phenomena, in terms of the dispersion relation for the complex frequency and wave number (ω, k) of disturbances in the mean field of the...
I introduce the idea of using neutrinos as probes for measuring the size of the solar core. I review previous work showing that neutrinos from galactic supernovae, detected in water Cherenkov experiments such as Super Kamiokande, can be used to locate their sources. Using these ideas I discuss my recent work in Phys.Rev.Lett. 117 (2016) 211101 on the prospects for measuring the size of the...
Galactic supernovae are rare, just a few per century, so it is important to be prepared. If we are, then the long-baseline detector DUNE could detect thousands of events, compared to the tens from SN 1987A. An important question is backgrounds from muon-induced spallation reactions. We simulate particle energy-loss processes in liquid argon, and compare relevant isotope yields with those in...
Super-Kamiokande (SK), the world's largest underground water Cherenkov detector, observes about 2 muons a second passing through it at a depth of 1 km. A fraction of these muons shower, and sometimes create radioactive isotopes (spallation). Those isotopes live anywhere from microseconds to several seconds, forming a dominant background to neutrino searches above 6 MeV and below 20 MeV....
NOvA is a long-baseline neutrino oscillation experiment with the
primary goals of discovering CP violation in the neutrino sector,
determining the neutrino mass hierarchy and constraining the mixing
angle $\theta_{23}$. NOvA also has a rich program of cosmic ray and
astrophysical measurements. We will set competitive limits on the
flux of magnetic monopoles as well as for neutrinos...
Neutrinos from charmed hadrons produced by cosmic ray interactions with air nuclei are the main background to high energy astrophysical neutrino flux measurements. Recent evaluations of the prompt neutrino flux from charm will be reviewed, including approaches using next-to-leading order QCD, the dipole model and kT factorization. Nuclear corrections and the impact of multi-component models of...
The DeepCore infill array of the IceCube Neutrino Observatory enables observations of atmospheric neutrinos with energies as low as 5 GeV. Using a set of 40,000 neutrino events with energies ranging from 5.6 - 56 GeV recorded during three years of DeepCore operation, we measure the atmospheric oscillation parameters $\theta_{23}$ and $\Delta m^2_{32}$ with precision competitive with...
As is well known, dark matter direct detection experiments will ultimately be limited by a "neutrino floor," due to the scattering of nuclei by MeV neutrinos from, e.g., nuclear fusion in the Sun. Here we point out the existence of a new "neutrino floor" that will similarly limit indirect detection with the Sun, due to high-energy neutrinos from cosmic-ray interactions with the solar...
High-energy neutrinos are expected to be produced in cosmic-ray interactions with the solar atmosphere. The resulting neutrino flux is expected to offer insights into cosmic ray transport in the inner solar system and on solar magnetic fields. Besides the high theoretical interest in solar atmospheric neutrinos, an observed signal could be the first high-energy neutrino point source and...
In this talk I will discuss the production of high-energy neutrinos from interactions of cosmic rays with the solar atmosphere. Production of solar atmospheric neutrinos has been previously considered in the literature both as a potential source of high-energy neutrinos and as an irreducible background for dark matter searches. In our new calculation we estimate the uncertainties that arise...
IceCube is a cubic kilometer scale detector in the deep antarctic ice. The 5160 deployed digital optical modules lead to the unambiguous detection of astrophysical neutrinos using events starting inside the detector with deposited energies above 60 TeV. Lowering the energy threshold down to 1 TeV, while maintaining a >90% neutrino-pure sample, greatly increases statistics. We will present the...
We report a new measurement of the diffuse flux of high energy extraterrestrial neutrinos from the whole sky with energies of O(1 TeV) and above, that is predominantly sensitive to electron and tau flavors. We analyzed 4 years of IceCube data recorded from 2012-2015 focusing on neutrino-induced cascades. Cascades provide good energy resolution and have a lower atmospheric neutrino background...
The IceCube neutrino observatory has observed a flux of high-energy astrophysical neutrinos using both track events from muon neutrino interactions and cascade events from interactions of all neutrino flavors. Searches for astrophysical neutrino sources have focused on track events due to the significantly better angular resolution of track reconstructions. To date, no such sources have been...
PeV neutrinos detected by the IceCube observatory are the highest-energy extraterrestrial elementary particles ever seen on Earth. More knowledge on PeV neutrinos such as seeing a spectral cut-off would help understand the possible connection to the sources of ultra-high energy cosmic rays. A new selection has been developed for PeV neutrinos which are not selected by the existing high-energy...
Neutrino interactions occurring in IceCube require accurate reconstruction techniques to quantify the neutrino's energy and arrival direction. At the highest energies, the angular resolution of IceCube is limited primarily by ice property uncertainties. Previous studies have shown that a perfect knowledge of the ice may improve cascade angular resolutions by a factor of two or more. We present...
IceCube analyses which look for an astrophysical neutrino signal in the southern sky face a large background of atmospheric neutrinos and muons created in cosmic ray air showers. Earlier, it was found that rejecting events that deposit energy in the outer region of the detector reduces not only the muon background, but also the atmospheric neutrino background in the southern sky due to the...
We present prospects for IceCube to detect neutrino emission from Galactic TeV gamma-ray sources outlined in the HAWC Observatory's recently published 2HWC catalog. We do this by evaluating the sensitivity of two analyses using IceCube data. The first is a stacked analysis of promising point sources from the catalog which are chosen based on their high TeV photon fluxes and lack of association...
Neutrino interactions, though feeble, are tremendously important in particle physics and astrophysics. Still, at neutrino energies above ~350 GeV there has been, up to now, no direct experimental information on neutrino interactions; calculations rely on extrapolations from lower energies. Now, for the first time, we can measure the neutrino-nucleon cross section at the TeV scale and above,...
IceCube observation of high-energy astrophysical neutrinos has opened the astrophysical neutrino window. As we accumulate statistics IceCube not only starts characterizing the astrophysical neutrino component, but also makes improved measurements of the highest energy atmospheric neutrinos. In this talk I will discuss how we can use both high-energy atmospheric neutrinos as well as...
The origin of the observed extraterrestrial neutrinos is still unknown, and their arrival directions are compatible with an isotropic distribution. This observation, together with dedicated studies of Galactic plane correlations, suggest a predominantly extragalactic origin. Dark matter-neutrino interactions, which have been extensively studied in cosmology, would thus lead to a slight...
Some Planck-scale physics and quantum gravity models predict a slight violation of Lorentz invariance (LIV) at high energies. High-energy cosmic neutrino observations can be used to test for such LIV. Operators in an effective field theory (EFT) can be used to describe the effects of LIV. They can be used to describe kinematically allowed energy losses of possible superluminal neutrinos. These...
We study Lorentz violation effects to flavor transitions of high energy astrophysical neutrinos. It is shown that the appearance of Lorentz violating Hamiltonian can drastically change the flavor transition probabilities of
astrophysical neutrinos. Predictions of Lorentz violation effects to flavor compositions of astrophysical neutrinos arriving on Earth are compared with IceCube flavor...
If dark energy is some kind of scalar field rather than a cosmological constant and can interact with the neutrino sector, it might cause CPT/Lorentz violating effects and also modifies the neutrino oscillation phenomenology. The effects will be insignificantly small compared to the ordinary oscillation effect at low energies, but might become visible in very high energies, since the terms in...
Neutrino spectral indices Galactic vs. Extra-galactic sources, and potential use of Glashow events are analyzed.
The IceCube neutrino discovery was punctuated by three showers with $E_\nu$ ~ 1-2 PeV. Interest is intense in possible fluxes at higher energies, though a marked lack of $E_\nu$ ~ 6 PeV Glashow resonance events implies a spectrum that is soft and/or cutoff below ~few PeV. However, IceCube recently reported a through-going track event depositing 2.6 $\pm$ 0.3 PeV. A muon depositing so much...
After the discovery of extraterrestrial high-energy neutrinos, the next major goal of neutrino telescopes will be identifying astrophysical objects that produce them. The flux of the brightest source Fmax, however, cannot be probed by studying the diffuse neutrino intensity. We aim at constraining Fmax by adopting a broken power-law flux distribution, a hypothesis supported by observed...
Neutrinos from supernovae (SNe) are crucial probes of explosive phenomena at the deaths of massive stars and neutrino physics. High-energy neutrinos are produced through hadronic processes by cosmic rays, which can be accelerated during interaction between the SN ejecta and circumstellar material (CSM). We investigate high-energy neutrino emission from Galactic SNe. Recent observations of...
Type IIn supernovae (SNe) explode in dense circumstellar media that have been modified by the SNe progenitors at their last evolutionary stages. The interaction of the freely expanding SN ejecta with the circumstellar medium gives rise to a shock wave propagating in the dense SN environment, which may accelerate protons to multi-PeV energies. Inelastic proton-proton collisions between the...
Star-forming and starburst galaxies are among candidate sources of high energy neutrino flux detected in the IceCube experiment. Previous studies mainly used simple correlations between gamma-ray and infrared luminosities and assume a common value of gamma-ray spectral index for all starburst galaxies, though it should depend on properties of individual galaxies. In this work, we present a new...
High energy neutrinos have been detected by IceCube, but their origin remains a mystery. Determining the sources of this flux is a crucial first step towards multi-messenger studies. In this work we systematically compare two classes of sources with the data: galactic and extragalactic. We build a likelihood function on an event by event basis including energy, event topology, absorption, and...
The ANTARES neutrino telescope has operated in the Mediterranean deep sea for roughly ten years. Its goal is to search for astrophysical neutrinos, both as a diffuse flux and originating from possible point sources. ANTARES is complementary to other neutrino observatories such as IceCube because of its good angular resolution and distinctive sky coverage. The ANTARES science program also...
The IceCube Neutrino Observatory has detected the first high-energy neutrinos of astrophysical origin, characterized its diffuse flux, and performed point- source searches throughout the sky. Now, a next-generation, in-ice Cherenkov telescope is being designed with increased sensitivities to high-energy neutrinos. IceCube-Gen2 will encompass about 8 cubic-kilometers of ice at the South Pole....
The ANtarctic Impulsive Transient Antenna (ANITA) is a long-duration
balloon experiment with an interferometric radio payload. ANITA scans
Antarctic ice for Askaryan radio emission from interactions of
extremely-high-energy (>1 EeV) cosmogenic neutrinos. ANITA is also
sensitive to geomagnetic radio emission from extensive air showers
(EAS) initiated by both ultra-high-energy cosmic rays and...
The Antarctic Impulsive Transient Antenna (ANITA) is a NASA long-duration balloon experiment
with the primary goal of detecting ultra-high-energy ($>10^{18}\,\mbox{eV}$) neutrinos via the Askaryan Effect.
The fourth ANITA mission, ANITA-IV, recently flew from Dec 2 to Dec 29, 2016.
The most significant change in signal processing in ANITA-IV from previous flights was the inclusion of the...
ANITA is a NASA balloon-borne radio (200-1200 MHz) telescope with a primary goal of detecting coherent radio emission from ultra-high-energy (UHE) neutrinos. The instrument is also sensitive to detect radio impulses produced by cosmic ray induced extensive air showers. ANITA-4 flew Dec 2, 2016 and landed Dec 29, 2016 after 28 days.
This talk will present the ANITA-IV instrument, flight...
The Askaryan Radio Array (ARA) is a gigaton, ultra-high energy (>10 PeV) radio neutrino detector under construction at South Pole; it searches for the characteristic radio Cherenkov pulses that are produced by neutrino interactions in the dense polar ice. The array has deployed three of the proposed ~37 stations so far, at depths up to 200m. In this talk, we will summarize the current status...
The Probe Of Extreme Multi-Messenger Astrophysics (POEMMA) mission is being designed to establish charged particle astronomy with ultra-high energy cosmic rays (UHECRs) and to observe astrophysical and cosmogenic neutrinos using both fluorescence and Cherenkov emission from extensive air-showers (EAS). The POEMMA design combines the concept developed for the Orbiting Wide-field...
Two ultrahigh-energy ($>10^{17}$ eV) neutrino detectors are being deployed in Antarctica: the Askaryan Radio Array (ARA) and the Antarctic Ross Ice-Shelf Antenna Neutrino Array (ARIANNA). As the experiments differ in both the design and the surrounding ice, we describe the progress of a joint effort to understand the importance of these differences and we demonstrate convergent results in...
The ARIANNA experiment is designed to observe cosmogenic neutrinos with energies in excess of 10^16 eV. The design envisions a grid of over 1000 independent radio detector stations, using high-gain log-periodic dipole antennas just below the surface to measure the characteristic Askaryan radio pulses from particle cascades generated in the ice by these neutrinos. Spaced a kilometer apart, this...
The Giant Radio Array for Neutrino Detection (GRAND) aims at detecting ultra-high-energy extraterrestrial neutrinos via the extensive air showers induced by the decay of tau leptons created in the interaction of neutrinos under the Earth's surface. Consisting of an array of $\sim 10^5$ radio antennas deployed over $\sim 2\cdot 10^5\,\mbox{km}^2$, GRAND plans to reach, for the first time, a...
The predictions of the flux of cosmogenic neutrinos at $10^{9}$ GeV are pretty
solid and solely depend on the composition of the primary flux of cosmic-rays
above $10^{10}$ GeV. Pushing the experimental sensitivity into the predicted
flux levels is a challenge and the hunt to detect the first cosmogenic neutrino
is ongoing. A major obstacle for experiments is to get a large enough...
Cosmogenic neutrinos produced by cosmic rays during propagation are expected to arrive at Earth in roughly equal ratios of electron, muon, and tau neutrinos. Due the cyclic regeneration of tau neutrinos and tau leptons, radio-based experiments are sensitive to the air showers produced by tau leptons emerging from the interaction of Earth-skimming tau neutrinos. We present a study of the...
