Flavoured Large N Gauge Theory on a Compact Space with an External Magnetic Field

TL;DR

This paper explores the phase structure of flavoured N=2 SYM on a three sphere under an external magnetic field, revealing phase transitions, magnetic catalysis, and meson spectrum phenomena including Zeeman splitting and Goldstone modes.

Contribution

It provides a detailed analysis of the interplay between magnetic fields and phase transitions in flavoured N=2 SYM on a compact space, highlighting new phenomena like magnetic catalysis and meson spectrum behavior.

Findings

First order phase transition between confined and deconfined phases.

Magnetic catalysis leads to a stable confined phase at strong magnetic fields.

Meson spectra show Zeeman splitting, level crossing, and a Goldstone boson at strong magnetic fields.

Abstract

The phase structure of flavoured N=2 SYM on a three sphere in an external magnetic field is studied. The pairing effect of the magnetic field competes with the dissociating effect of the Casimir free energy, leading to an interesting phase structure of confined and deconfined phases separated by a critical curve of a first order quantum phase transition. At vanishing magnetic field the phase transition is of a third order. For sufficiently strong magnetic field, the only stable phase is the confined phase and magnetic catalysis of chiral symmetry breaking is realized. The meson spectra of the theory exhibit Zeeman splitting and level crossing and feature a finite jump at the phase transition between the confined and deconfined phases. At strong magnetic field the ground state has a massless mode corresponding to the Goldstone boson associated with the spontaneously broken U(1) R-symmetry analogous to the eta' meson in QCD.