Holographic QCD Running Coupling for Light Quarks in Strong Magnetic Field

TL;DR

This paper studies how the running coupling constant in a holographic QCD model varies with magnetic field, chemical potential, and temperature, revealing significant dependencies and phase transition behaviors.

Contribution

It introduces a holographic model incorporating magnetic fields and analyzes the running coupling's dependence on external parameters, aligning with lattice results at zero chemical potential.

Findings

Running coupling decreases with increasing magnetic field.

Phase transitions cause jumps in the running coupling.

Dependence of phase transition location on boundary conditions.

Abstract

We consider running coupling constant in holographic model with external magnetic field supported by Einstein-dilaton-three-Maxwell action. We obtain a significant dependence of the running coupling constant $\alpha$ on chemical potential, temperature and magnetic field. We use the boundary condition that ensures the agreement with lattice calculations of string tension between quarks at zero chemical potential. The location of the 1st order phase transitions in $(\mu, T)$-plane does not depend on the dilaton boundary conditions. We observe that running coupling $\alpha$ decreases with increasing magnetic field for the fixed values of chemical potential and temperature. At the 1st order phase transitions the functions $\alpha$ undergo jumps depending on temperature, chemical potential and magnetic field.