A Perturbative Realization of Miransky Scaling

Preprint number: CP3-Origins-2012-15 and DIAS-2012-16
Authors: Oleg Antipin (CP3-Origins & DIAS), Stefano Di Chiara (CP3-Origins & DIAS), Matin Mojaza (CP3-Origins & DIAS), Esben Mølgaard (CP3-Origins & DIAS), and Francesco Sannino (CP3-Origins & DIAS)
External link: arXiv.org

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Near conformal dynamics is employed in di erent extensions of the standard model of particle interactions as well as in cosmology. Many of its interesting properties are either conjectured or determined using model computations. We introduce a relevant four dimensional gauge theory template allowing us to investigate such dynamics perturbatively. The gauge theory we consider is quantum chromodynamics with the addition of a meson-like scalar degree of freedom as well as an adjoint Weyl fermion.

At the two-loop level, and in the Veneziano limit, we firmly establish the existence of several fixed points of which one is all directions stable in the infrared. An interesting feature of the model is that this fixed point is lost, within the perturbatively trustable regime, by merging with another fixed point when varying the number of quark flavors. We show the emergence of the Miransky scaling and determine its properties. We are also able to determine the walking region of the theory which turns out to be, at large number of colors, about 12% of the conformal window. Furthermore, we determine highly relevant quantities for near conformal dynamics such as the anomalous dimension of the fermion masses.