Long-range magnetic fields in the ground state of the Standard Model plasma

TL;DR

The paper demonstrates that in the Standard Model plasma, non-zero global charges induce an instability leading to the formation of large-scale magnetic fields, driven by weak interactions and chiral anomaly effects, potentially impacting early Universe evolution.

Contribution

It reveals a novel mechanism where global charges cause magnetic field generation in the Standard Model plasma due to parity violation and chiral anomaly effects.

Findings

Homogeneous plasma states become unstable with non-zero global charges.

Large-scale magnetic fields can form in the early Universe.

Weak interactions and chiral anomaly drive the magnetic field generation.

Abstract

In thermal equilibrium the ground state of the plasma of Standard Model particles is determined by temperature and exactly conserved combinations of baryon and lepton numbers. We show that at non-zero values of the global charges a translation invariant and homogeneous state of the plasma becomes unstable and the system transits into a new state, containing a large-scale magnetic field. The origin of this effect is the parity-breaking character of weak interactions and chiral anomaly. This situation can occur in the early Universe and may play an important role in its subsequent evolution.