# Spin Hydrodynamic Generation in the Charged Subatomic Swirl

## TL;DR

This paper proposes a novel mechanism linking fluid vorticity to magnetic field generation in charged subatomic fluids, offering an explanation for observed polarization differences between particles and anti-particles in heavy ion collisions.

## Contribution

It introduces a new way of generating magnetic fields in relativistic nuclear collisions by connecting fluid vorticity to magnetic field creation, explaining experimental polarization puzzles.

## Key findings

- Magnetic field arises naturally along fluid vorticity in charged subatomic fluids.
- The mechanism explains the polarization difference between particles and anti-particles.
- Provides a long-lived in-medium magnetic field in heavy ion collisions.

## Abstract

Recently there have been significant interests in the spin hydrodynamic generation phenomenon from multiple disciplines of physics. Such phenomenon arises from global polarization effect of microscopic spin by macroscopic fluid rotation and is expected to occur in the hot quark-gluon fluid (the ``subatomic swirl'') created in relativistic nuclear collisions. This was indeed discovered in experiments which however revealed an intriguing puzzle: a polarization difference between particles and anti-particles. We suggest a novel application of a general connection between rotation and magnetic field: a magnetic field naturally arises along the fluid vorticity in the charged subatomic swirl. We establish this mechanism as a new way for generating long-lived in-medium magnetic field in heavy ion collisions. Due to its novel feature, this new magnetic field provides a nontrivial explanation to the puzzling observation of a difference in spin hydrodynamic generation for particles and anti-particles in heavy ion collisions.