Flavoured large N gauge theory on a compact space with an external magnetic field

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 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 η meson in QCD.

Inverse magnetic catalysis in holographic models of QCD

“…Recently, the study of the QCD phase diagram for magnetic field B has attracted considerable attention [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19], see [20] for a review. The main motivation for studying the QCD phase diagram under external magnetic field B stems from the fact that strong magnetic field B is produced in heavy ion collisions experiments at RHIC eB ∼ 0.01 GeV 2 and LHC eB ∼ 0.25 GeV 2 [21], due to the charged spectator particles, which has interesting effects on the quark-gluon plasma created during these heavy ion collision experiments [22][23][24][25][26][27], see [20] for a review.…”

“…Regarding the study of the QCD phase diagram for magnetic field B, most of the models for QCD [1][2][3][4][5][6][7][8][9][10], including the holographic ones [11][12][13][14][15][16], have studied chiral-symmetryrestoration transition and have predicted that the critical temperature T c of the transition increases with increasing magnetic field B at zero chemical potential µ = 0. This enhancing effect of the magnetic field B on the critical temperature T c has been termed magnetic catalysis.…”

Flavours in global Klebanov-Witten background

“…[13][14][15] for thermodynamic studies with external control parameters. 4 For studies of the flavoured Klebanov-Witten model in the Poincare patch, relevant to our studies, see refs.…”

“…In equation (2.13) g is the determinant of the induced metric g µν , given by: 14) and γ µ 1 ...µ p+1 is an antisymmetrised product of the induced gamma matrices γ µ , given by: 15) where EN M are the components of the one-form frame given in equation (2.7). The τ a matrices in equation (2.13) are Pauli matrices acting on the vector ε 1 ε 2 , where ε 1 and ε 2 are the real and imaginary parts of the complex spinor ε.…”

Equilibrium instability of chiral mesons in external electromagnetic field via AdS/CFT

“…However, the magnetic field alone does not play such a role in the system. According to the meson spectroscopy, the mesons mass is changed by the influence of electric and magnetic field [16,26,[30][31][32][33]. Although the meson spectrum is altered in the background magnetic field, it can not dissociate the mesons.…”