Holographic Description of Chiral Symmetry Breaking in a Magnetic Field in 2+1 Dimensions with an Improved Dilaton

Research paper by Diego M. Rodrigues, Danning Li, Eduardo Folco Capossoli, Henrique Boschi-Filho

Indexed on: 09 Nov '18Published on: 09 Nov '18Published in: arXiv - High Energy Physics - Phenomenology

Abstract

We consider a holographic description of the chiral symmetry breaking in an external magnetic field in $(2+1)$-dimensional gauge theories from the softwall model using an improved dilaton field profile given by $\Phi(z) = - kz^2 + (k+k_1)z^2\tanh (k_{2}z^2)$. We find inverse magnetic catalysis for $B<B_c$ and magnetic catalysis for $B>B_c$, where $B_c$ is the pseudocritical magnetic field. The transition between these two regimes is a crossover and occurs at $B=B_c$, which depends on the fermion mass and temperature. We also find spontaneous chiral symmetry breaking at $T=0$ in the chiral limit ($m_q\to 0$) and chiral symmetry restoration for finite temperatures.