Intrinsic charm contribution to the prompt atmospheric neutrino flux
In this work we investigate the impact of intrinsic charm on the prompt atmospheric neutrino flux. The color dipole approach to heavy quark production is generalized to include the contribution of processes initiated by charm quarks. The prompt neutrino flux is calculated assuming the presence of intrinsic charm in the wave function of the projetile hadron. The predictions are compared with previous color dipole results which were obtained taking into account only the process initiated by gluons. In addition, we estimate the atmospheric (conventional + prompt) neutrino flux and compare our predictions with the ICECUBE results for the astrophysical neutrino flux. Our results demonstrate that the contribution of the charm quark initiated process is non - negligible and that the prompt neutrino flux can be enhanced by a factor $\approx$ 2 at large neutrino energies if an intrinsic charm component is present in the proton wave function.