Related papers: Walking in the SU(N)
Four $SU(5)$ $N=1$ supersymmetric models which exhibit $S_3$ and/or $Z_N$ symmetries are studied, that are finite to two or all loops, and their corresponding mass matrices. The first is an all-loop finite model based on an $S_3\times…
We have performed numerical simulations of SU(3) gauge theory coupled to Nf=2 flavors of symmetric representation fermions. The fermions are discretized with the tadpole-improved clover action. Our simulations are done on lattices of length…
We discuss the properties of non-abelian gauge theories formulated on manifolds with compactified dimensions and in the presence of fermionic fields coupled to magnetic backgrounds. We show that different phases may emerge, corresponding to…
We analyse descriptions of electroweak symmetry breaking in terms of ultralocal antisymmetric tensor fields and gauge-singlet geometric variables, respectively; in particular, the Weinberg--Salam model and, ultimately, dynamical electroweak…
We examine the role of the center Z(N) of the gauge group SU(N) in gauge theories. In this pedagogical article, we discuss, among other topics, the center symmetry and confinement and deconfinement in gauge theories and associated…
In the worldline approach to non-Abelian field theory the colour degrees of freedom of the coupling to the gauge potential can be incorporated using worldline "colour" fields. The colour fields generate Wilson loop interactions whilst…
QCD with 2 flavours of massless colour-sextet quarks is studied as a theory which might exhibit a range of scales over which the running coupling constant evolves very slowly (walks). We simulate lattice QCD with 2 flavours of sextet…
We investigate a supersymmetric theory with an extra U(1) gauge symmetry surviving down to low energies. The extra U(1) is assumed to originate from an E$_6$ grand unified theory (GUT). We show that if one assumes universal soft…
Computer simulations show that liquids of molecules with harmonic intramolecular bonds may have "pseudoisomorphic" lines of approximately invariant dynamics in the thermodynamic phase diagram. We demonstrate that these lines can be…
Considered is the N=1 SQCD-like theory with SU(N_c) colors and 0<N_F<2N_c flavors of light quarks Q_i,\bar Q_j and with the additional N^2_F colorless flavored fields Phi_{ij} with the large mass parameter \mu_{Phi}>>Lambda. The mass…
We extend the results of [arXiv:1006.0207 [hep-lat]] by computing the S-parameter at two loops in the perturbative region of the conformal window. Consistently using the expression for the location of the infra-red fixed point at the…
We investigate a family of four-dimensional quantum field theories with weakly interacting ultraviolet fixed points up to four loop order in perturbation theory. Key new ingredients are the three loop gauge contributions to quartic scalar…
We study the nature of the finite-temperature transition of the three-dimensional scalar chromodynamics with N_f flavors. These models are constructed by considering maximally O(M)-symmetric multicomponent scalar models, whose symmetry is…
I report the results of a series of works on the phase diagram of theories with a different number of colors and/or quarks in a different representation than in QCD. Similarities as well as differences as compared to the real world are…
Dynamical electro-weak symmetry breaking is an appealing, strongly-coupled alternative to the weakly-coupled models based on an elementary scalar field developing a vacuum expectation value. In the first two sections of this set of…
We study QCD with 2 and 3 flavours of colour-sextet quarks. The 2-flavour theory is a candidate Walking Technicolor theory. Since we are attempting to distinguish whether this theory is walking or conformal, we also study the 3-flavour…
We study asymptotically free SU($N_c$) gauge theories with ${\cal N}=1$ supersymmetry, including the purely gluonic theory and theories with $N_f$ copies of a pair of massless chiral superfields in the respective representations $R$ and…
We consider the $SU(2)$ gauge theory with $N_f=2$ flavors of Dirac fundamental fermions. We study the high-temperature behavior of the spectra of mesons, discretizing the theory on anisotropic lattices, and measuring the two-point…
Simulations of four-dimensional SU(2) lattice gauge theory are performed with partial axial gauge fixing trees spanning three of the four dimensions. The remaining SU(2) gauge symmetry, global in three directions and local in one, is found…
The quark exchange model is a simple realization of an adiabatic approximation to the strong-coupling limit of Quantum Chromodynamics (QCD): the quarks always coalesce into the lowest energy set of flux tubes. Nuclear matter is thus modeled…