Nuclear Corrections in ν A DIS and Their Compatibility with Global NPDF Analyses

Abstract

We perform a global χ2-analysis of nuclear parton distribution functions using data from charged current neutrino–nucleus (νA) deep inelastic scattering (DIS), charged-lepton–nucleus (l±A) DIS, and the Drell–Yan (DY) process. We show that the nuclear corrections in νA DIS are not compatible with the predictions derived from l±A DIS and DY data. We quantify this result using a hypothesis-testing criterion based on the χ2 distribution which we apply to the total χ2 as well as to the χ2 of the individual data sets. We find that it is not possible to accommodate the data from νA and l±A DIS by an acceptable combined fit. This implies that either the twist-2 parton distribution functions in nuclei are not universal, or that higher-twist terms play a more important role in the nuclear environment and have to be taken into account.