Correlations between the deconfining and chiral transitions in holographic QCD
Yingying Li, Xing-Lin Liu, Xin-Yi Liu, Zhen Fang
Abstract
We consider an improved soft-wall AdS/QCD model coupled to an Einstein-dilaton system, which offers a way to study the deconfining and chiral transitions simultaneously. The correlation between these two transitions has been investigated in detail in the Einstein-dilaton-scalar system with the bulk scalar field representing the vacuum of matters in the flavor sector of the model. We find that the effects of the scaling dimension $\mathrm{\ensuremath{\Delta}}$ of the dual operator of the dilaton manifest in chiral transitions, although the equations of state can all be matched with the two-flavor lattice results for $\mathrm{\ensuremath{\Delta}}=2.5,3,3.5$ in the decoupling case of $\ensuremath{\beta}=0$. In the weak-coupling case with smaller $\ensuremath{\beta}$, both the equation of state and the chiral transition exhibit a crossover behavior and turn into first-order phase transitions with the increase of $\ensuremath{\beta}$.