On the prompt contribution to the atmospheric neutrino flux

The prompt contribution to the atmospheric neutrino flux is analyzed. We demonstrate that the corresponding theoretical uncertainties related to perturbative treatment of charm production, notably, the ones stemming from the low- and high-x behavior of parton distribution functions, can be conveniently studied at the level of charm quark production. Additionally, we discuss the nonperturbative contribution to the prompt neutrino flux, related to the intrinsic charm content of the proton and analyze its main features.