Measurement of the AtmosphericνeFlux in IceCube

Abstract

We report the first measurement of the atmospheric electron neutrino flux in the energy range between approximately 80 GeV and 6 TeV, using data recorded during the first year of operation of IceCube's DeepCore low-energy extension. Techniques to identify neutrinos interacting within the DeepCore volume and veto muons originating outside the detector are demonstrated. A sample of 1029 events is observed in 281 days of data, of which 496±66(stat)±88(syst) are estimated to be cascade events, including both electron neutrino and neutral current events. The rest of the sample includes residual backgrounds due to atmospheric muons and charged current interactions of atmospheric muon neutrinos. The flux of the atmospheric electron neutrinos is consistent with models of atmospheric neutrinos in this energy range. This constitutes the first observation of electron neutrinos and neutral current interactions in a very large volume neutrino telescope optimized for the TeV energy range.

Non-standard interactions with high-energy atmospheric neutrinos at IceCube

“…After a few years of operation, statistics have been accumulated and a number of studies of atmospheric neutrinos have been performed. Atmospheric neutrino flux measurements have been carried out in a wide range of energies [112][113][114][115][116][117], low-energy atmospheric neutrino data have been considered to constrain neutrino oscillation parameters to levels comparable to other neutrino oscillation experiments [51,52], low-energy data have also been used to set constraints on matter NSI [49], and light sterile neutrinos, claimed as possible explanations of short baseline Figure 8. Posterior (68% and 95%) probability contours for two 10-year forecasts of high-energy atmospheric neutrino data in IceCube.…”

Neutrino fluxes from dark matter in the HESS J1745-290 source at the Galactic center

“…The ν μ and ν e atmospheric neutrinos have been reported by IceCube [29,30]. The electronic neutrino background has limited data with important uncertainties.…”

“…In particular, the data were collected with an exposition time of t ν μ exp ¼ 359 days and t ν e exp ¼ 281 days for the muon and electron neutrinos, respectively [29,30]. We have found that for DM annihilating into the W þ W − boson channel, we need a resolution angle 0.18°≲ θ ≲ 0.72°and low-energy cutoff 818 GeV ≲ E ν min ≲ 1811 GeV to get a signal between 5σ and 2σ with a minimum of 2 years of exposition time and a maximum of 5 years for an effective detector area of 50 m 2 .…”

“…As we have commented, we are assuming that the neutrino detector will not be able to distinguish between neutrinos and antineutrinos [29]. So the neutrino flux Φ ν α is understood to be the sum of ν α andν α .…”

On the angular distribution of IceCube high‐energy events

“…Whatever the source, the angular distribution of events is considered consistent with an isotropic arrival direction of neutrinos (Aartsen et al 2013c(Aartsen et al , 2014a and the majority of events detected by IceCube are believed to be from cosmological distances or, less likely, from the Galactic halo. In a recent update, Aartsen et al (2014b) have found no evidence of neutrino emission from discrete or extended sources in four years of IceCube data.…”