Neutrino collective excitations are studied in the Standard Model at high temperatures below the symmetry breaking scale. Two parameters determine the properties of the collective excitations: a mass scale m_ν=gT/4 which determines the chirally symmetric gaps in the spectrum and Δ=M^2_W(T)/2m_ν T. The spectrum consists of left handed negative helicity quasiparticles, left handed positive helicity quasiholes and their respective antiparticles. For Δ < Δ_c = 1.275... there are two gapped

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... icle branches and one gapless and two gapped quasihole branches, all but the higher gapped quasiparticle branches terminate at end points. For Δ_c < Δ < π/2 the quasiparticle spectrum features a pitchfork bifurcation and for Δ >π/2 the collective modes are gapless quasiparticles with dispersion relation below the light cone for k≪ m_ν approaching the free field limit for k≫ m_ν with a rapid crossover between the soft non-perturbative to the hard perturbative regimes for k∼ m_ν.The decay of the vector bosons leads to a width of the collective excitations of order g^2 which is explicitly obtained in the limits k =0 and k≫ m_νΔ. At high temperature this damping rate is shown to be competitive with or larger than the collisional damping rate of order G^2_F for a wide range of neutrino energy.