Chiral phase transition at finite temperature and conformal dynamics in large N-f QCD

We investigate the chiral phase transition at finite temperature (T) in colour SU(Nc = 3) Quantum Chromodynamics (QCD) with a variable number of fermions Nf in the fundamental representation by using lattice QCD. For Nf = 6 we study the approach to asymptotic scaling by considering lattices with several temporal extensions Nt. We then extract the dimensionless ratio Tc/L (L = Lattice Lambda-parameter) for Nf = 6 and Nf = 8, the latter relying on our earlier results. Further, we collect the (pseudo) critical couplings c L for the chiral phase transition at Nf = 0 (quenched), and Nf = 4 at a fixed Nt = 6. The results are consistent with enhanced fermionic screening at larger Nf . The ratio Tc/L depends very mildly on Nf in the Nf = 0 − 4 region, starts increasing at Nf = 6, and becomes significantly larger at Nf = 8, close to the edge of the conformal window. We discuss interpretations of these results as well as their possible interrelation with preconformal dynamics in the light of a functional renormalization group analysis