Large-x Parton Distributions

TL;DR

This paper reviews the current understanding of large-x parton distributions, highlighting recent measurements and global fits that aim to reduce uncertainties and improve predictions for future collider experiments.

Contribution

It provides an updated analysis of large-x parton distributions using new data and explores the potential of future experiments to further constrain these distributions.

Findings

Uncertainty in large-x parton distributions has been reduced by recent measurements.

Global fits show improved constraints on gluon and quark distributions at large x.

Future HERA data could significantly refine large-x parton distribution knowledge.

Abstract

Reliable knowledge of parton distributions at large x is crucial for many searches for new physics signals in the next generation of collider experiments. Although these are generally well determined in the small and medium x range, it has been shown that their uncertainty grows rapidly for x > 0.1. We examine the status of the gluon and quark distributions in light of new questions that have been raised in the past two years about large-x parton distributions, as well as recent measurements which have improved the parton uncertainties. We perform several specific global fits to answer the outstanding questions, and to investigate the potential of future experiments, particularly at HERA, which may provide critical constraints on parton distributions at large x.