Deconfinement transition of AdS/QCD at O(α/3)

We study the confinement/deconfinement phase transition of holographic AdS/QCD models by using Ricci flat AdS(5) black holes up to O(alpha(/3)), which corresponds to the lambda expansion correction in the dual field theory to lambda(-3/2), where lambda is the 't Hooft coupling constant. We consider two cases: one is the hard-wall AdS/QCD model where a small radius region of the AdS(5) is removed; the other is the case where one of the spatial coordinates for the AdS(5) space is compactified, resulting in Witten's QCD model in 2+1 dimensions. We find that in the hard-wall AdS/QCD model, the deconfinement temperature decreases when the lambda expansion corrections are taken into account, while in Witten's QCD model, the deconfinement transition always happens when the ratio of inverse temperature ss to the period ss(s) of the compactified coordinate decreases to one, ss/ss(s)=1, the same as the case without the O(alpha(/3)) correction.