Mass anomalous dimension in sextet QCD
Abstract
We extend our previous study of the SU(3) gauge theory with Nf=2 flavors of fermions in the sextet representation of color. Our tool is the Schroedinger functional method. By changing the lattice action, we push the bulk transition of the lattice theory to stronger couplings and thus reveal the beta function and the mass anomalous dimension gammam over a wider range of coupling, out to g2 ~ 11. Our results are consistent with an infrared fixed point, but walking is not ruled out. Our main result is that gammam never exceeds 0.45, making the model unsuitable for walking technicolor. We use a novel method of extrapolation to the large-volume/continuum limit, tailored to near-conformal theories.
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