Problem with parton-model descriptions of neutrino data?

Abstract

The present results from $\nu N$ and $\overline{\nu }N$ scattering experiments appear to place conflicting requirements on conventional quark-parton models. The strong rise with energy of ${〈y〉}^{\overline{\nu }N}$ and $\frac{{\sigma }_T^{\overline{\nu }N}}{{\sigma }_T^{\nu N}}$ seems to require new-particle (charm) production from valence quarks in $\overline{\nu }N$ interactions, whereas the $x$ dependence of dimuon events and the $\frac{d\sigma }{\mathrm{dy}}$ anomaly suggest that $\overline{\nu }N$ 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 $m_c=1.5\mathrm{}$ GeV, $m_b=5\mathrm{}$ GeV, and a higher $t$-quark mass.