About possible contribution of intrinsic charm component to inclusive spectra of charmed mesons

We calculate differential energy spectra (x(F)-distributions) of charmed particles produced in proton-nucleus collisions, assuming the existence of intrinsic heavy quark components in the proton wavefunction. For the calculation, the recently proposed factorization scheme is used, based on the colour glass condensate theory and specially suited for predictions of a production of particles with large rapidities. It is argued that the intrinsic charm component can, if it exists, dominate in a sum of two components, intrinsic + extrinsic, of the inclusive spectrum of charmed particles produced in proton-nucleus collisions at high energies, in the region of medium x(F), 0.15 < x(F) < 0.7, and can give noticeable contribution to atmospheric fluxes of prompt muons and neutrinos.