High-energy neutrino conversion and the lepton asymmetry in the universe

Cecilia Lunardini, A. Yu Smirnov

Research output: Contribution to journalArticle

84 Citations (Scopus)

Abstract

We study the matter effects on oscillations of high-energy neutrinos in the Universe. A substantial effect can be produced by scattering of the neutrinos from cosmological sources (Formula presented) on the relic neutrino background, provided that the latter has large (Formula presented) asymmetry: (Formula presented) where (Formula presented) (Formula presented) and (Formula presented) are the concentrations of neutrinos, antineutrinos, and photons. We consider in detail the dynamics of conversion in the expanding neutrino background. Applications are given to the diffuse fluxes of neutrinos from gamma ray bursters, active galactic nuclei, and the decay of superheavy relics. We find that the vacuum oscillation probability can be modified by (Formula presented) and in extreme cases allowed by present bounds on (Formula presented) the effect can reach (Formula presented) The signatures of matter effects would consist (i) for both active-active and active-sterile conversion, in a deviation of the numbers of events produced in a detector by neutrinos of different flavors, (Formula presented) (Formula presented) and of their ratios from the values given by vacuum oscillations; such deviations can reach (Formula presented) and (ii) for active-sterile conversion, in a characteristic energy dependence of the ratios (Formula presented) Searches for these matter effects will probe large (Formula presented) and lepton asymmetries in the Universe.

Original languageEnglish (US)
Number of pages1
JournalPhysical Review D - Particles, Fields, Gravitation and Cosmology
Volume64
Issue number7
DOIs
StatePublished - Jan 1 2001
Externally publishedYes

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leptons
neutrinos
universe
asymmetry
energy
oscillations
deviation
vacuum
antineutrinos

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Physics and Astronomy (miscellaneous)

Cite this

High-energy neutrino conversion and the lepton asymmetry in the universe. / Lunardini, Cecilia; Smirnov, A. Yu.

In: Physical Review D - Particles, Fields, Gravitation and Cosmology, Vol. 64, No. 7, 01.01.2001.

Research output: Contribution to journalArticle

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