Non critical holographic models of the thermal phases of QCD

We analyze the thermal phases of a non critical holographic model of QCD. The model is based on a six dimensional background of Nc non extremal D4 branes wrapping a spacial circle of radius R and the compactified Euclidean time direction of radius β = 1/T . We place in this background stacks of Nf D4 and anti-D4 flavor probe branes with a separation distance L at large radial direction. The analysis of the DBI effective action yields the following phase diagram: At low temperature the system is in a confining phase with broken chiral symmetry. In the high temperature deconfining phase chiral symmetry can be either restored for L > Lc = 1.06R or broken for L < Lc. All of these phase transitions are of first order. We analyze the spectrum of the low-spin and high-spin mesons. High spin mesons above certain critical angular momentum “melt”. We detect (no) drag for ( mesons) quarks moving in hot quark-gluon fluid. The results resemble the structure and properties of the thermal Sakai-Sugimoto model derived in hep-th/0604161.