Holographic QCD and quarkonium melting: Finite temperature, density, and external field effects in self-consistent dynamical models

TL;DR

This dissertation develops a self-consistent holographic QCD model to study how heavy mesons behave and melt under finite temperature, density, and magnetic fields, revealing phase transitions and magnetic effects on quarkonium stability.

Contribution

It introduces a novel dynamical holographic QCD model incorporating finite temperature, density, and magnetic fields, providing new insights into meson melting and phase transitions.

Findings

Finite temperature causes confinement-deconfinement transition.

Higher chemical potential accelerates meson melting.

Magnetic fields induce a shift from inverse magnetic catalysis to magnetic catalysis.

Abstract

This MSc dissertation is based on the papers arXiv:2502.12694 and arXiv:2408.14813. The AdS/CFT correspondence provides a powerful framework for modeling strongly coupled gauge theories and, as a consequence, investigating non-perturbative phenomena in QCD. In this work, following an overview of the ideas that encapsulate the AdS/CFT correspondence, we present a self-consistent dynamical holographic QCD model within the Einstein-Maxwell-dilaton framework, derived from the coupled field equations, to study the mass spectra and melting behavior of heavy and exotic mesons at finite temperature and density. Finite temperature analyses reveal a confinement-deconfinement transition and sequential quarkonia melting. At finite density, an increase in chemical potential accelerates meson melting, with spectral functions evolving smoothly across the phase transition line. Finally, using a nonlinear Einstein-Born-Infeld-dilaton model, magnetic field effects demonstrate a shift from inverse magnetic catalysis to magnetic catalysis, highlighting the impact of spatial anisotropy on quarkonium stability.