Probing Very High Energy Prompt Muon and Neutrino fluxes and the cosmic ray knee via Underground Muons

We calculate event rate and demonstrate the observational feasibility of very high energy muons (1-1000 TeV) in a large mass underground detector operating as a pair-meter. This energy range corresponds to surface muon energies of $\sim$(5 TeV - 5000 TeV) and primary cosmic ray energies of $\sim$ (50 TeV - 5 $\times 10^4$ TeV). Such measurements would significantly assist in an improved understanding of the prompt contribution to $\nu_e, \nu_{\mu}$ and $\mu$ fluxes in present and future ultra-high energy neutrino detectors. In addition, they would shed light on the origin of the observed 'knee' in the cosmic ray spectrum.