Neutrino fluxes from astrophysical sources, the role of neutrinos from charmed meson production and decay

We show that charm production gives significant enhancement to a flux of very high energy neutrinos from astrophysical sources with jets driven by central engines, such as gamma ray bursts or supernovae with jets. We demonstrate that neutrino flux from semi-leptonic decays of charmed mesons is subject to much less hadronic and radiative cooling than the conventional flux from pion and kaon decays. We discuss implications of our results for future ultrahigh energy neutrino experiments.