0000000000822587
AUTHOR
R. Konietz
Constraints on ultra-high-energy cosmic ray sources from a search for neutrinos above 10 PeV with IceCube
We report constraints on the sources of ultra-high-energy cosmic ray (UHECR) above $10^{9}$ GeV, based on an analysis of seven years of IceCube data. This analysis efficiently selects very high energy neutrino-induced events which have deposited energies from $\sim 10^6$ GeV to above $10^{11}$ GeV. Two neutrino-induced events with an estimated deposited energy of $(2.6 \pm 0.3) \times 10^6$ GeV, the highest neutrino energies observed so far, and $(7.7 \pm 2.0) \times 10^5$ GeV were detected. The atmospheric background-only hypothesis of detecting these events is rejected at 3.6$\sigma$. The hypothesis that the observed events are of cosmogenic origin is also rejected at $>$99% CL because of…
Astrophysical neutrinos and cosmic rays observed by IceCube
The core mission of the IceCube neutrino observatory is to study the origin and propagation of cosmic rays. IceCube, with its surface component IceTop, observes multiple signatures to accomplish this mission. Most important are the astrophysical neutrinos that are produced in interactions of cosmic rays, close to their sources and in interstellar space. IceCube is the first instrument that measures the properties of this astrophysical neutrino flux and constrains its origin. In addition, the spectrum, composition, and anisotropy of the local cosmic-ray flux are obtained from measurements of atmospheric muons and showers. Here we provide an overview of recent findings from the analysis of Ic…
The IceCube realtime alert system
Following the detection of high-energy astrophysical neutrinos in 2013, their origin is still unknown. Aiming for the identification of an electromagnetic counterpart of a rapidly fading source, we have implemented a realtime analysis framework for the IceCube neutrino observatory. Several analyses selecting neutrinos of astrophysical origin are now operating in realtime at the detector site in Antarctica and are producing alerts to the community to enable rapid follow-up observations. The goal of these observations is to locate the astrophysical objects responsible for these neutrino signals. This paper highlights the infrastructure in place both at the South Pole detector site and at IceC…
Neutrino oscillation studies with IceCube-DeepCore
IceCube, a gigaton-scale neutrino detector located at the South Pole, was primarily designed to search for astrophysical neutrinos with energies of PeV and higher. This goal has been achieved with the detection of the highest energy neutrinos to date. At the other end of the energy spectrum, the DeepCore extension lowers the energy threshold of the detector to approximately 10 GeV and opens the door for oscillation studies using atmospheric neutrinos. An analysis of the disappearance of these neutrinos has been completed, with the results produced being complementary with dedicated oscillation experiments. Following a review of the detector principle and performance, the method used to make…
PINGU: a vision for neutrino and particle physics at the South Pole
The Precision IceCube Next Generation Upgrade (PINGU) is a proposed low-energy in-fill extension to the IceCube Neutrino Observatory. With detection technology modeled closely on the successful IceCube example, PINGU will provide a 6Mton effective mass for neutrino detection with an energy threshold of a few GeV. With an unprecedented sample of over 60,000 atmospheric neutrinos per year in this energy range, PINGU will make highly competitive measurements of neutrino oscillation parameters in an energy range over an order of magnitude higher than long-baseline neutrino beam experiments. PINGU will measure the mixing parameters $\theta_{\rm 23}$ and $\Delta m^2_{\rm 32}$, including the octan…
Search for sterile neutrino mixing using three years of IceCube DeepCore data
Physical review / D 95(11), 112002(2017). doi:10.1103/PhysRevD.95.112002
Characterization of the atmospheric muon flux in IceCube
Muons produced in atmospheric cosmic ray showers account for the by far dominant part of the event yield in large-volume underground particle detectors. The IceCube detector, with an instrumented volume of about a cubic kilometer, has the potential to conduct unique investigations on atmospheric muons by exploiting the large collection area and the possibility to track particles over a long distance. Through detailed reconstruction of energy deposition along the tracks, the characteristics of muon bundles can be quantified, and individual particles of exceptionally high energy identified. The data can then be used to constrain the cosmic ray primary flux and the contribution to atmospheric …
Evidence for Astrophysical Muon Neutrinos from the Northern Sky with IceCube
Results from the IceCube Neutrino Observatory have recently provided compelling evidence for the existence of a high energy astrophysical neutrino flux utilizing a dominantly Southern Hemisphere dataset consisting primarily of nu_e and nu_tau charged current and neutral current (cascade) neutrino interactions. In the analysis presented here, a data sample of approximately 35,000 muon neutrinos from the Northern sky was extracted from data taken during 659.5 days of livetime recorded between May 2010 and May 2012. While this sample is composed primarily of neutrinos produced by cosmic ray interactions in the Earth's atmosphere, the highest energy events are inconsistent with a hypothesis of …
Measurement of the AtmosphericνeSpectrum with IceCube
We present a measurement of the atmospheric $\nu_e$ spectrum at energies between 0.1 TeV and 100 TeV using data from the first year of the complete IceCube detector. Atmospheric $\nu_e$ originate mainly from the decays of kaons produced in cosmic-ray air showers. This analysis selects 1078 fully contained events in 332 days of livetime, then identifies those consistent with particle showers. A likelihood analysis with improved event selection extends our previous measurement of the conventional $\nu_e$ fluxes to higher energies. The data constrain the conventional $\nu_e$ flux to be $1.3^{+0.4}_{-0.3}$ times a baseline prediction from a Honda's calculation, including the knee of the cosmic-…