Holographic chiral phase transition with chemical potential

Abstract

We discuss the Sakai-Sugimoto model at finite temperature and finite chemical potential. It is a holographic model of large N_c QCD with N_f massless quarks based on a D4/D8-\bar{D8} brane system. The near horizon limit of the D4-branes and the probe approximation of the D8-\bar{D8} pairs allow us to treat the D4-branes as a gravitational background and the D8-\bar{D8} pairs as a probe which does not affect the background. We propose that the asymptotic value of a U(1) gauge field on the D8-\bar{D8}-branes is identified with the chemical potential for the baryon number. Using this chemical potential we analyze the phase structure of this model and find a chiral symmetry phase transition of the first order.

Figures (6)

• Figure 1: The phase diagram of the dual gauge theory.
• Figure 2: A D8-$\overline{\text{D8}}$-brane configuration in the low temperature phase.
• Figure 3: D8-$\overline{\text{D8}}$-brane configurations in the high temperature phase.
• Figure 4: $\Delta S$ as a function of $u_T$ for various values of $c$. From the bottom to the top each line represents the case for $c =$ 0, 0.2158, 0.2252, 0.3 respectively.
• Figure 5: The phase diagram in the $c$-$u_T$ space.