Chiral and deconfinement transitions in spin-polarized quark matter

TL;DR

This paper explores how spin polarization affects the phase transitions in strongly interacting quark matter, revealing that increased spin polarization lowers the transition temperatures and can induce a first-order chiral transition, aligning with lattice QCD results.

Contribution

It introduces a finite spin potential in an effective QCD model to study spin effects, providing new insights into the QCD phase diagram under spin-polarized conditions.

Findings

Increased spin polarization lowers chiral and deconfinement transition temperatures.

A first-order chiral phase transition appears at low temperature with high spin polarization.

Results align qualitatively with recent lattice QCD simulations.

Abstract

We investigate the influence of spin polarization in strongly interacting matter by introducing a finite spin potential, $\mu_\Sigma$, which effectively controls the spin density of the system without requiring rotation or specific boundary conditions. Inspired by recent lattice QCD simulations that incorporated such a potential, we implement this approach within an effective QCD framework. Our results show that increasing spin polarization leads to a simultaneous decrease in both the chiral and deconfinement restoration temperatures. The resulting phase structure is qualitatively consistent with lattice findings, and notably, we observe the emergence of a first-order chiral phase transition at low temperature. These results suggest that spin-polarized environments can significantly impact the QCD phase diagram and offer a controlled route for studying spin effects in hot and dense matter.