Nucleon structure at large x: nuclear effects in deuterium

TL;DR

This paper reviews how nuclear effects in deuterium influence the extraction of the d/u quark distribution ratio at high momentum fractions, revealing significant suppression of the d quark when nuclear corrections are included.

Contribution

It introduces a new global analysis of parton distributions with relaxed kinematic cuts, highlighting the importance of nuclear effects in understanding nucleon structure at large x.

Findings

Nuclear effects significantly suppress the d quark distribution at high x.

Relaxed kinematic cuts in the analysis lead to stronger nuclear correction effects.

The d/u ratio at large x is substantially affected by nuclear corrections.

Abstract

I review quark momentum distributions in the nucleon at large momentum fractions x. Particular attention is paid to the impact of nuclear effects in deuterium on the d/u quark distribution ratio as x -> 1. A new global study of parton distributions, using less restrictive kinematic cuts in Q^2 and W^2, finds strong suppression of the d quark distribution once nuclear corrections are accounted for.