Pion-nucleus Drell-Yan data as a novel constraint for nuclear PDFs

Understand

We have studied the prospects of using the Drell-Yan dilepton process in pion-nucleus collisions as a novel input in the global analysis of nuclear parton distribution functions (nPDFs).

• In a NLO QCD framework, we find the measured nuclear cross-section ratios from the NA3, NA10 and E615 experiments to be largely insensitive to the pion parton distributions and also compatible with the EPS09 and nCTEQ15 nPDFs.
• These data sets can thus be, and in EPPS16 have been, included in global nPDF analyses without introducing significant new theoretical uncertainties or tension with the other data.
• In particular, we explore the constraining power of these data sets on the possible flavour asymmetry in the valence-quark nuclear modifications.