Mu-tau neutrino refraction and collective three-flavor transformations in supernovae
9 pages, 6 figures.-- PACS nrs.: 14.60.Pq; 97.60.Bw.-- ArXiv pre-print available at: http://arxiv.org/abs/0712.1137 ; We study three-flavor collective neutrino transformations in the dense-neutrino region above the neutrino sphere of a supernova core. We find that two-flavor conversions driven by the atmospheric mass difference and the 13-mixing angle capture the full effect if one neglects the second-order difference between the Vm and Vp refractive index. Including this ''mu-tau matter term'' provides a resonance at a density of P= 3 x 10(7) g cm-3 that typically causes significant modifications of the overall Ve and Ve survival probabilities. This effect is surprisingly sensitive to deviations from maximal 23-mixing, being different for each octant. ; We thank E. Akhmedov for an illuminating correspondence, A. Mirizzi for comments on the manuscript, and B. Dasgupta and A. Dighe for helpful comments and for making their manuscript [22] available before completion. This work was partly supported by the eutsche Forschungsgemeinschaft (Grant No. TR-27 ''Neutrinos and Beyond''), by the Cluster of Excellence ''Origin and Structure of the Universe'' (Garching and Munich), by the European Union (Contracts No. RII3-CT-2004-506222 and No. MRTN-CT-2004-503369), and by the Spanish Grants No. FPA2005-01269 (MEC) and No. ACOMP07-270 (Generalitat Valenciana). A. E. was supported by an FPU grant from the Spanish Government. S. P. and R. T. were supported by MEC contracts (Ramo´n y Cajal and Juan de la Cierva, respectively). ; Peer reviewed