Gennady Voronov

The SU(2) gauge theories with N f flavors of massless vector-like Dirac fermions transforming in the pseudo-real fundamental representation have an enhanced global chiral symmetry and a distinct symmetry breaking pattern. These theories are expected to be qualitatively different from quantum chromodynamics (QCD) in the infrared (IR), especially with respect to properties of the Nambu Goldstone bosons (NGBs). Having the potential to elucidate many features of both known and conjectured… Show more

The SU(2) gauge theories with N f flavors of massless vector-like Dirac fermions transforming in the pseudo-real fundamental representation have an enhanced global chiral symmetry and a distinct symmetry breaking pattern. These theories are expected to be qualitatively different from quantum chromodynamics (QCD) in the infrared (IR), especially with respect to properties of the Nambu Goldstone bosons (NGBs). Having the potential to elucidate many features of both known and conjectured strongly-coupled physics, these theories ought to be investigated. Here I study the Nf = 6 theory, which is expected to lie near the lower edge of the conformal window. A determination of whether this specific theory is inside the window holds the promise of revealing a great deal of the structure of this interesting class of theories.

Toward this end, I compute the running gauge coupling in the non-perturbative Schrodinger functional (SF) scheme. This computation is performed numerically with lattice simulations of the SU(2) lattice gauge theory with six flavors of stout-smeared Wilson fermions. I find no evidence for an infrared fixed point (IRFP) up through renormalized gauge couplings g¯2 of order 20. This implies that the theory either is governed by an IRFP of considerable strength, unseen so far in non-supersymmetric gauge theories, or breaks its global chiral symmetries producing a large number of composite NGBs relative to the number of underlying degrees of freedom. Thus either of these phases exhibits novel behavior. Show less

Using lattice simulations, we study the infrared behavior of a particularly interesting SU(2) gauge theory, with six massless Dirac fermions in the fundamental representation. We compute the running gauge coupling derived non-perturbatively from the Schrodinger functional of the theory, finding no evidence for an infrared fixed point up through gauge couplings of order 20. This implies that the theory either is governed in the infrared by a fixed point of considerable strength, unseen so far in… Show more

Using lattice simulations, we study the infrared behavior of a particularly interesting SU(2) gauge theory, with six massless Dirac fermions in the fundamental representation. We compute the running gauge coupling derived non-perturbatively from the Schrodinger functional of the theory, finding no evidence for an infrared fixed point up through gauge couplings of order 20. This implies that the theory either is governed in the infrared by a fixed point of considerable strength, unseen so far in non-supersymmetric gauge theories, or breaks its global chiral symmetries producing a large number of composite Nambu-Goldstone bosons relative to the number of underlying degrees of freedom. Thus either of these phases exhibits novel behavior. Show less