Introduction The IceCube Collaboration revisited six previous studies investigating the nature of the astrophysical neutrino flux in a combined maximum-likelihood analysis that used up to three observables—energy, zenith angle and event topology—to derive improved constraints on the energy spectrum and the composition of neutrino flavors (νe , νμ , ντ) of the astrophysical neutrino flux. […]
data release
Search for point sources with first year of IC86 data
Introduction IceCube performed a search for point-like sources of neutrinos using four years of IceCube data, including the first year of data from the completed 86-string detector, taken between May 2011 and May 2012. The search did not identify a single source, but the sensitivity was significantly improved from both the additional year of data […]
Search for sterile neutrinos with one year of IceCube data
Introduction The IceCube neutrino telescope at the South Pole has measured the atmospheric muon neutrino spectrum as a function of zenith angle and energy to search for the oscillation signatures of light sterile neutrinos. No evidence for anomalous vμ or v –μ disappearance is observed in either of two independently developed analyses, each using one year of atmospheric neutrino data. […]
The 79-string IceCube search for dark matter
Introduction Searches for high-energy neutrinos from the Sun are currently the most sensitive means of probing spin-dependent interactions between protons and most models for dark matter. In 2013, the IceCube Collaboration published the world’s best limits on the spin-dependent cross section for weakly interacting dark matter particles. Today, we present an improved event-level likelihood formalism […]
Observation of Astrophysical Neutrinos in Four Years of IceCube Data
Introduction The spectrum of cosmic rays includes the most energetic particles ever observed. The mechanism of their acceleration and their sources are, however, still mostly unknown. Observing astrophysical neutrinos can help solve this problem. Because neutrinos are produced in hadronic interactions and are neither absorbed nor deflected, they will point directly back to their source. […]
Astrophysical muon neutrino flux in the northern sky with 2 years of IceCube data
Introduction 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 data set consisting primarily of νe and ντ charged-current and neutral-current (cascade) neutrino interactions. In the analysis presented here, a data sample of approximately 35000 muon neutrinos from […]
IceCube-59: Search for point sources using muon events
Introduction A search for neutrino point sources using 3 years of IceCube data, including the 59-string configuration (May 2009 – May 2010), was performed. An all-sky scan was performed to look for spatial clustering of a fitting for the flux level and the spectral index. No significant hotspots were found. For more information on the […]
Search for contained neutrino events at energies greater than 1 TeV in 2 years of data
Introduction The IceCube Neutrino Observatory was designed primarily to search for high-energy (TeV–PeV) neutrinos produced in distant astrophysical objects. A search for >100 TeV neutrinos interacting inside the instrumented volume has recently provided evidence for an isotropic flux of such neutrinos. At lower energies, IceCube collects large numbers of neutrinos from the weak decays of […]
IceCube Oscillations: 3 years muon neutrino disappearance data
Introduction In the 1990s, Super-Kamiokande’s measurements of atmospheric neutrinos led to the acceptance of the mass-induced oscillation model. As of today, the three mixing angles, the solar mass splitting and the absolute value of the atmospheric mass splitting that control the oscillation phenomenon have been measured. The existence of CP-violation and the ordering of the […]
Search for contained neutrino events at energies above 30 TeV in 2 years of data
Introduction Neutrino observations are a unique probe of the universe’s highest energy phenomena: neutrinos are able to escape from dense environments that photons cannot and are unambiguous tracers of hadronic interaction processes, in particular the acceleration of cosmic rays. As cosmic ray protons and nuclei are accelerated, they interact with gas and background light to […]