HIGH ENERGY NEUTRINOS FROM ACCELERATORS OF COSMIC RAY NUCLEI

摘要

Ongoing experimental efforts to detect cosmic sources of high energy neutrinos are guided by the expectation that astrophysical accelerators of cosmic ray protons also generate high energy neutrinos through their interactions with ambient matter and/or photons. However the predicted neutrino flux is reduced if cosmic ray sources accelerate not only protons but also a significant number of heavier nuclei, as is indicated by recent air shower data. I consider two plausible extragalactic class of sources, active galactic nuclei and gamma-ray bursts, and demand consistency with the observed cosmic ray composition and energy spectrum at Earth after allowing for propagation through intergalactic radiation fields. This allows me to calculate the degree of photo-disintegration and pion production expected to occur in these sources, and hence the neutrino fluxes from them.