@Article{Mena_etal2014, author="Mena, O. and Palomares-Ruiz, S. and Vincent, A. C.", title="Flavor Composition of the High-Energy Neutrino Events in IceCube", journal="Physical Review Letters", year="2014", publisher="Amer Physical Soc", volume="113", number="9", pages="091103--5pp", abstract="The IceCube experiment has recently reported the observation of 28 high-energy (> 30 TeV) neutrino events, separated into 21 showers and 7 muon tracks, consistent with an extraterrestrial origin. In this Letter, we compute the compatibility of such an observation with possible combinations of neutrino flavors with relative proportion (alpha(e:)alpha(mu):alpha tau)(circle plus). Although the 7: 21 track-to-shower ratio is naively favored for the canonical (1:1:1)(circle plus) at Earth, this is not true once the atmospheric muon and neutrino backgrounds are properly accounted for. We find that, for an astrophysical neutrino E-2 energy spectrum, (1:1:1)(circle plus). at Earth is disfavored at 81{\%} C. L. If this proportion does not change, 6 more years of data would be needed to exclude (1:1:1)(circle plus) at Earth at 3 sigma C.L. Indeed, with the recently released 3-yr data, that flavor composition is excluded at 92{\%} C. L. The best fit is obtained for (1:0:0)(circle plus). at Earth, which cannot be achieved from any flavor ratio at sources with averaged oscillations during propagation. 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.", optnote="WOS:000341292800005", optnote="exported from refbase (https://references.ific.uv.es/refbase/show.php?record=1920), last updated on Thu, 02 Oct 2014 11:13:12 +0000", issn="0031-9007", doi="10.1103/PhysRevLett.113.091103", opturl="http://arxiv.org/abs/arXiv:1404.0017", opturl="https://doi.org/10.1103/PhysRevLett.113.091103", archivePrefix="arXiv", eprint="arXiv:1404.0017", language="English" }