相关论文: Running coupling in SU(2) with adjoint fermions
I report the results of Schroedinger functional calculations in the SU(3) gauge theory with two flavors of color sextet fermions, defined with the Wilson-clover action using nHYP fat links. While we cannot confirm the infrared fixed point…
We discuss a new approach for putting gauge theories on the lattice. The gauge fields are defined on the lattice only, but are interpolated to the interior of the lattice cells, where they couple to continuum fermions. The purpose of this…
When designing lattice actions, gauge field smearing is frequently used to define the lattice Dirac operator. Since the smearing procedure removes effects of ultraviolet fluctuations, the fermions effectively see a larger lattice spacing…
The electromagnetic coupling receives significant contributions to its running from non-perturbative QCD effects. We present an update of a lattice QCD study of the Adler function and of its application to the determination of the running…
A recently proposed method for a strong coupling analysis of scattering phenomena in hamiltonian lattice field theories is applied to the $\SU2$ Yang-Mills model in $(2+1)$ dimensions. The calculation is performed up to second order in the…
Motivated by recent scenarios of exotic infrared behaviour and by earlier lattice findings, we present results for the SU(2) gauge theory with one Dirac flavor in the adjoint representation. This provides a major update on our previous…
We investigate the discrete $\beta$ function of the 2-flavor SU(3) sextet model using the finite volume gradient flow scheme. Our results, using clover improved nHYP smeared Wilson fermions, follow the (non-universal) 4-loop…
SU(2) gauge theory is investigated with a lattice action which is insensitive to small perturbations of the lattice gauge fields. Bare perturbation theory can not be defined for such actions at all. We compare non-perturbative continuum…
The set-up of the QCD Schr\"odinger functional (SF) on the lattice with staggered quarks requires an even number of points $L/a$ in the spatial directions, while the Euclidean time extent of the lattice, $T/a$, must be odd. Identifying a…
Non-Abelian gauge theories with fermions transforming in the adjoint representation of the gauge group (AdjQCD) are a fundamental ingredient of many models that describe the physics beyond the Standard Model. Two relevant examples are N=1…
We study the global symmetries of SU(2) gauge theory with N flavors of staggered fermions in the presence of a chemical potential. We motivate the special interest of the case N=1 (staggered) with fermions in the adjoint representation of…
We show the running coupling as derived from the SU(3) QQ potential and discuss preliminary results on spin dependent heavy quark potentials from high statistics lattice simulations of SU(2) gauge theory. The precision suffices to study…
We present results of quenched $SU(3)$ hadron spectroscopy comparing $\order(a)$ improved Wilson (Clover) fermions with conventional Wilson fermions. The configurations were generated using an $\order(a^2)$ improved 6-link $SU(3)$ pure…
For N>4 there is a first order bulk transition that cleanly separates the strong and weak coupling regimes of SU(N) lattice gauge theories with the plaquette action. We find that in this case the calculated string tension can be readily…
We perturbatively determine O($a$) boundary improvement coefficients at 1-loop for the Schr\"odinger Functional coupling with improved gauge actions. These coefficients are required to implement the 1-loop O($a$) improvement in full QCD…
Recently the Lattice Strong Dynamics Collaboration reported a reduction of the electroweak S parameter for SU(3) gauge theory with Nf=6 fermions in the fundamental representation, compared to scaled-up QCD (arXiv:1009.5967). Here I provide…
We study the SU(2) gauge theory on the lattice with different numbers of fermions in the fundamental representation of the gauge group to explore the gauge theory phase diagram. We find evidence for an infrared fixed point for ten flavors.…
We determine non-perturbatively the fixed-point action for fermions in the two-dimensional U(1) gauge (Schwinger) model. This is done by iterating a block spin transformation in the background of non-compact gauge field configurations…
Using a tadpole improved SU(2) gluodynamics action, the nonabelian potential and the abelian potential after the abelian projection are computed. Rotational invariance is found restored at coarse lattices both in the nonabelian theory and…
We report some preliminary results of our ongoing non-perturbative computation of the twisted 't Hooft running coupling in a particular set-up, using the gradient flow to define the coupling and step scaling techniques to compute it. For…