Where do we stand with a 3-D picture of the proton?

TL;DR

This paper reviews recent progress and ongoing challenges in creating multi-dimensional images of the proton, highlighting key achievements and future directions from both theoretical and experimental perspectives.

Contribution

It provides a condensed overview of significant recent developments and open challenges in the quest to obtain a detailed 3-D picture of the proton.

Findings

Multiple recent achievements in proton imaging

Identification of key open challenges

Summary of theoretical and experimental progress

Abstract

We are on the way to obtaining multi-dimensional "pictures" of the proton. The field is bursting with activities, both from the theoretical and experimental side. A brief selection of important achievements of the last years and open challenges for the future is presented. They are already well documented in the various reviews of this Special Issue, but they are gathered here in a more condensed way for convenience, together with some additional remarks. The choice of the items included in this short overview is far from being complete and represents the view of the author.