Contributions to the quark flavor and spin observables from the intrinsic charm in the proton are discussed in the SU(4) quark meson fluctuation model. Our results suggest that the probability of finding the intrinsic charm in the proton is less than 1%. The intrinsic charm helicity is small and negative, Δc≃−(0.003∼0.015). The fraction of the total quark helicity carried by the intrinsic charm is less than 2%, and c\up/c\dw=35/67.
@article{arxiv.hep-ph/0109289,
title = {Intrinsic Charm Flavor and Helicity Content in the Proton},
author = {Xiaotong Song},
journal= {arXiv preprint arXiv:hep-ph/0109289},
year = {2009}
}