Minkowski's lost legacy and hadron electromagnetism

TL;DR

This paper revisits Minkowski's work on relativistic electromagnetism to clarify the charge distribution in hadrons, resolving longstanding puzzles by connecting classical multipole moments to hadronic charge densities.

Contribution

It demonstrates how classical relativistic electromagnetism explains the charge distributions in hadrons, challenging the traditional non-relativistic definitions.

Findings

Traditional charge distribution definitions are invalid for relativistic systems.

Various hadronic charge distributions emerge as multipole moments in relativistic electromagnetism.

The work links classical electromagnetism with hadronic physics insights.

Abstract

We revisit Minkowski's lost legacy on relativistic electromagnetism in order to resolve long-standing puzzles over the charge distribution of relativistic systems like hadrons. Hadrons are unique relativistic electromagnetic systems characterized by their comparable size and Compton wavelength $r_h \sim \lambda_C$. As such, it was recently realized that the traditional Sachs definition of the charge distribution based on a non-relativistic formula is invalid. We explain that this is the same problem pursued by Lorentz, Einstein and others, on the electromagnetism of a moving body. We show how various charge distributions proposed in hadronic physics naturally emerge as the multipole moment densities in the macroscopic theory of relativistic electromagnetism.