Heavy-flavor contributions at NNLO in CTEQ PDF analysis
  We discuss an NNLO realization of the general mass scheme S-ACOT-$\chi$ for treatment of heavy-flavour production in neutral current deep-inelastic scattering. Practical implementation of the NNLO calculation is illustrated on the example of semi-inclusive structure functions $F_{2 c}(x,Q)$ and $F_{L c}(x,Q)$. 
Marco Guzzi, Pavel M. Nadolsky, Hung-Liang Lai and C.-P. Yuan
hep-ph