Real and Virtual Compton Scattering: the nucleon polarisabilities

TL;DR

This paper reviews low-energy real and virtual Compton scattering experiments that probe the nucleon's internal structure and its deformation under electromagnetic fields, focusing on nucleon polarisabilities and recent experimental progress.

Contribution

It provides a comprehensive overview of nucleon polarisabilities, including recent experimental results and future research directions in the context of real and virtual Compton scattering.

Findings

Summarizes current knowledge of nucleon polarisabilities

Highlights ongoing experiments and future prospects

Discusses the generalization to non-zero four-momentum transfer

Abstract

We give an overview of low-energy Compton scattering (gamma^(*) p --> gamma p) with a real or virtual incoming photon. These processes allow the investigation of one of the fundamental properties of the nucleon, i.e. how its internal structure deforms under an applied static electromagnetic field. Our knowledge of nucleon polarisabilities and their generalization to non-zero four-momentum transfer will be reviewed, including the presently ongoing experiments and future perspectives.