Problem with parton-model descriptions of neutrino data?

The present results from νN and νN scattering experiments appear to place conflicting requirements on conventional quark-parton models. The strong rise with energy of 〈y〉^νN and σT^νNσT^νN seems to require new-particle (charm) production from valence quarks in νN interactions, whereas the x dependence of dimuon events and the dσdy anomaly suggest that νN charm production comes from sea quarks. No single model gives a fully satisfactory explanation of all the present data. We draw attention to this problem, illustrate the conflicting requirements of data with particular models, and discuss possible resolutions. The closest overall compromise with the present data is obtained with the six-quark model, using charm-quark masses mc=1.5 GeV, mb=5 GeV, and a higher t-quark mass.