6533b7ddfe1ef96bd1273f99
RESEARCH PRODUCT
On the flavor composition of the high-energy neutrinos in IceCube
Olga MenaSergio Palomares-ruizAaron C. VincentAaron C. Vincentsubject
High Energy Astrophysical Phenomena (astro-ph.HE)PhysicsNuclear and High Energy PhysicsHigh energyParticle physicsMuon010308 nuclear & particles physicsAstrophysics::High Energy Astrophysical PhenomenaHigh Energy Physics::PhenomenologyFOS: Physical scienceshigh-energy neutrinos01 natural sciencesIceCubeHigh Energy Physics - PhenomenologyHigh Energy Physics - Phenomenology (hep-ph)flavor ratios0103 physical sciencesEnergy spectrumHigh Energy Physics::ExperimentNeutrino010306 general physicsAstrophysics - High Energy Astrophysical PhenomenaFlavordescription
The IceCube experiment has recently released 3 years of data of the first ever detected high-energy (>30 TeV) neutrinos, which are consistent with an extraterrestrial origin. In this talk, we compute the compatibility of the observed track-to-shower ratio with possible combinations of neutrino flavors with relative proportion (alpha_e:alpha_mu:alpha_tau). Although this observation is naively favored for the canonical (1:1:1) at Earth, once we consider the IceCube expectations for the atmospheric muon and neutrino backgrounds, this flavor combination presents some tension with data. We find that, for an astrophysical neutrino E_nu^{-2} energy spectrum, (1:1:1) at Earth is currently disfavored at 92% C.L. We discuss the trend of this result by comparing the results with the 2-year and 3-year data. We obtain the best-fit for (1:0:0) at Earth, which cannot be achieved from any flavor ratio at sources with averaged oscillations during propagation. Although it is not statistically significant at present, if confirmed, this result would suggest either a misunderstanding of the expected background events, or a misidentification of tracks as showers, or even more compellingly, some exotic physics which deviates from the standard scenario.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2016-04-01 | Nuclear and Particle Physics Proceedings |