Speaker
Description
The flavor composition of high-energy astrophysical neutrinos encodes information about their production and propagation. The Glashow resonant interaction $\bar{\nu}e+e^-\to W^-$, provides a unique way to distinguish antineutrinos from neutrinos, which extends the reach of flavor composition studies. Proposed tau air-shower neutrino telescopes target Earth-skimming and mountain-skimming neutrinos above PeV. Through $W^-\to\bar{\nu}\tau+\tau^-$, such experiments would also be sensitive to $\bar{\nu}e$ via the Glashow resonant interaction. In this work, we evaluate this prospect with explicit simulations and project sensitivities for TAMBO and TRINITY. We find that mountain-skimming geometries yield substantially higher $\bar{\nu}e$. While the $pp$ and $p\gamma$ scenarios remain challenging to distinguish with current designs, a $\bar{\nu}_e$-rich flux from neutron decay or new physics would stand out from pion-production scenarios and could otherwise be constrained.