Chiral phase transition of QCD with $N_f=2+1$ flavors from holography

Understand

Chiral phase transition for three-flavor $N_f=2+1$ QCD with $m_u=m_d\neq m_s$ is investigated in a modified soft-wall holographic QCD model.

• Solving temperature dependent chiral condensates from equations of motion of the modified soft-wall model, we extract the quark mass dependence of the order of chiral phase transition in the case of $N_f=2+1$, and the result is in agreement with the "Colombia Plot", which is summarized from lattice simulations and other non-perturbative methods.
• First order phase transition is observed around the three flavor chiral limit $m_{u/d}=0, m_{s}=0$, while at sufficient large quark masses it turns to be a crossover phase transition.
• The first order and crossover regions are separated by a second order phase transition line.