2013/11/12 by Y. Iwasaki, Iwasaki, Y.
Physics and Astronomy · #Black Holes and Theoretical Physics #FOS: Physical sciences #High Energy Physics - Lattice (hep-lat) #High Energy Physics - Phenomenology (hep-ph) #High Energy Physics - Theory (hep-th) #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions
paper · pdf · doi:10.48550/arxiv.1311.2966
openalex publication_date 2013/11/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We introduce a new concept "conformal theories with an IR cutoff", after pointing out that the following two categories in SU(3) gauge theories with fundamental Nf fermions possess an IR fixed point: Large Nf QCD with Nf in the conformal window (referred as Conformal QCD) and small Nf QCD with Nf out of the conformal window at temperature T/Tc > 1 (referred as High Temperature QCD). In the conformal theories with an IR cutoff there exists the "conformal region'" together with the confining region and the deconfining region. We verify numerically on a lattice of the size 163 x64 the existence of the conformal region and the non-trivial Z(3) structure of the vacuum and the Yukawa-type decay form of meson propagators in the conformal region. We stress that High Temperature QCD is intrinsically accompanied with an IR cutoff. Therefore the understanding the vacuum structure and the property of correlation functions is the key to resolve long standing issues in High Temperature QCD. We further argue that there is a precise correspondence between Conformal QCD and High Temperature QCD in the temporal propagators under the change of the parameters Nf and T/Tc respectively: the one boundary is close to meson states and the other is close to free quark states. In particular, we find the correspondence between Conformal QCD with Nf = 7 and High Temperature QCD with Nf=2 at T ~ 2 Tc being in close relation to a meson unparticle model. From this we estimate the anomalous mass dimension gamma* = 1.2 (1) for Nf=7.