Pion condensation in a dense neutrino gas

TL;DR

This paper explores how dense neutrino gases can be used to investigate the QCD phase diagram at finite isospin, revealing conditions for pion condensation and effects on pion properties.

Contribution

It demonstrates that a dense neutrino gas can induce pion Bose-Einstein condensation and affect pion degeneracy, providing a novel probe of QCD phases.

Findings

Pion Bose-Einstein condensate forms at high neutrino densities.

Neutrino density lifts degeneracy in pion masses and lifetimes.

Neutrino gases can probe QCD phase diagram regions.

Abstract

We argue that using an equilibrated gas of neutrinos it is possible to probe the phase diagram of QCD for finite isospin and small baryon chemical potentials. We discuss this region of the phase diagram in detail and demonstrate that for large enough neutrino densities a Bose-Einstein condensate of positively charged pions arises. Moreover, we show that for nonzero neutrino density the degeneracy in the lifetimes and masses of the charged pions is lifted.