Spontaneous magnetization under a pseudovector interaction between quarks in high density quark matter

TL;DR

This paper investigates how pseudovector interactions between quarks lead to spontaneous magnetization in high-density quark matter, revealing coexistence of condensates and magnetic properties at specific chemical potentials.

Contribution

It demonstrates the coexistence of chiral and spin polarized condensates and calculates spontaneous magnetization in quark matter using the NJL model.

Findings

Coexistence of chiral and spin polarized condensates in a narrow chemical potential region.

Spontaneous magnetization appears in this coexistence region.

Magnetic susceptibility of quarks is evaluated in the spin polarized phase.

Abstract

Spontaneous magnetization and magnetic susceptibility originated from the pseudovector-type four-point interaction between quarks are calculated in quark matter with zero temperature and finite quark chemical potential by using the two-flavor Nambu-Jona-Lasinio model. It is shown that both the chiral condensate and spin polarized condensate coexist in a narrow region of the quark chemical potential. And then, it is also shown that, in this narrow region, the spontaneous magnetization appears. Also, the magnetic susceptibility due to quarks with the positive energy is evaluated in the spin polarized phase.