Dense and magnetized QCD from imaginary chemical potential

TL;DR

This paper uses lattice QCD simulations at imaginary chemical potential to study the equation of state of dense QCD with magnetic fields, revealing significant effects near the crossover temperature relevant for heavy-ion collisions.

Contribution

It provides the first lattice QCD calculation of the dense QCD equation of state with magnetic fields at physical quark masses using imaginary chemical potential techniques.

Findings

Magnetic fields significantly alter the QCD equation of state near the crossover temperature.

The study demonstrates the feasibility of using imaginary chemical potential in lattice QCD for dense matter.

Results are relevant for modeling heavy-ion collision phenomenology.

Abstract

In this work, we computed the equation of state of dense QCD in the presence of background magnetic fields using lattice QCD simulations at imaginary baryon chemical potential. Our simulations include 2+1+1 flavors of stout-smeared staggered fermions with masses at the physical point and a tree-level Symanzik-improved gauge action. Using several expansion schemes, we tuned our simulation parameters such that the equation of state satisfies strangeness neutrality and isospin asymmetry constraints, which are relevant to the phenomenology of heavy-ion collisions. Our results suggest a strong change in the equation of state due to the magnetic field, in particular, around the crossover temperature. A continuum extrapolation of our data is still needed for future applications of our equation of state to heavy-ion-collision phenomenology.