  Theoretical predictions of the prompt atmospheric neutrino flux have large
uncertainties associated with charm hadron production, by far the dominant
source of prompt neutrinos in the atmosphere. The flux of cosmic rays, with its
steeply falling energy spectrum, weights the forward production of charm in the
evaluation of the atmospheric neutrino flux at high energies. The current LHCb
experiment at CERN constrains charm production in kinematic regions relevant to
the prompt atmospheric neutrino flux. The proposed Forward Physics Facility has
additional capabilities to detect neutrino fluxes from forward charm production
at the LHC. We discuss the implications of the current and planned experiments
on the development of theoretical predictions of the high energy atmospheric
neutrino flux.
