Searching for Long‐Wavelength Neutrino Oscillations in the Distorted Neutrino Spectrum of Galactic Supernova Remnants

Abstract

We investigate the muon neutrino event rate in km3 neutrino telescopes due to a number of galactic supernova remnants (SNRs) expected on the basis of these objects' known γ-ray signals. We evaluate the potential of such instruments to detect breaks in the expected power-law behavior of these SNRs' neutrino signals. Such breaks are, in particular, induced by the long-wavelength neutrino oscillations predicted by various neutrino mixing schemes including pseudo-Dirac scenarios and the exact parity model. With 10 years' data, neutrino signals from Sgr A East, alone, should either exclude neutrino oscillations governed by a δm2 parameter close to 10-15 eV2 or, alternatively, discover such oscillations in the likely event that other explanations for any observed break can be excluded. If data from γ-ray observations are included in the analysis, then oscillations governed by a δm2 in the approximate range from 10-13 to 10-15 eV2 might be discovered or excluded. Terrestrial or solar system neutrino experiments do not have the capability to observe oscillations governed by such tiny δm2 values.