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Related papers: Nonperturbative infrared fixed point in sextet QCD

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The methods of lattice gauge theory may be applied to gauge theories besides QCD, in fact to any gauge group and any representation of matter fields (as long as the coupling is not chiral). Such theories are useful for model building beyond…

High Energy Physics - Lattice · Physics 2010-02-25 Benjamin Svetitsky

We present new results from our ongoing study of the SU(3) sextet model with two flavors in the two-index symmetric representation of the gauge group. In the simulations use unimproved Wilson fermions to investigate the infrared properties…

High Energy Physics - Lattice · Physics 2017-09-13 Martin Hansen , Claudio Pica

We extend our previous study of the SU(3) gauge theory with N_f=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…

High Energy Physics - Lattice · Physics 2013-05-01 Thomas DeGrand , Yigal Shamir , Benjamin Svetitsky

Results are reported for the beta-function of weakly coupled conformal gauge theories on the lattice, SU(3) with Nf=14 fundamental and Nf=3 sextet fermions. The models are chosen to be close to the upper end of the conformal window where…

High Energy Physics - Lattice · Physics 2018-04-18 Zoltan Fodor , Kieran Holland , Julius Kuti , Daniel Nogradi , Chik Him Wong

An SU(2) gauge theory with two fermions transforming under the adjoint representation of the gauge group may appear conformal or almost conformal in the infrared. We use lattice simulations to study the spectrum of this theory and present…

High Energy Physics - Lattice · Physics 2009-05-12 Ari J. Hietanen , Jarno Rantaharju , Kari Rummukainen , Kimmo Tuominen

We have measured the running coupling constant of SU(3) gauge theory coupled to Nf=2 flavors of symmetric representation fermions, using the Schrodinger functional scheme. Our lattice action is defined with hypercubic smeared links which,…

High Energy Physics - Lattice · Physics 2014-11-21 Thomas DeGrand , Yigal Shamir , Benjamin Svetitsky

We apply Schroedinger functional methods to two gauge theories with fermions in two-index representations: the SU(3) theory with Nf=2 adjoint fermions, and the SU(4) theory with Nf=6 fermions in the two-index antisymmetric representation.…

High Energy Physics - Lattice · Physics 2013-09-25 Thomas DeGrand , Yigal Shamir , Benjamin Svetitsky

We present preliminary results of lattice simulations of SU(2) gauge theory with two Wilson fermions in the adjoint representation. This theory has recently attracted considerable attention because it might possess an infrared fixed point…

High Energy Physics - Lattice · Physics 2010-01-21 Ari Hietanen , Jarno Rantaharju , Kari Rummukainen , Kimmo Tuominen

We perform a lattice calculation of the Schr\"odinger functional running coupling in SU(2) Yang-Mills theory with six massless Wilson fermions in the fundamental representation. The aim of this work is to determine whether the above theory…

High Energy Physics - Lattice · Physics 2013-01-18 Gennady Voronov

We complete a program of study of SU(N) gauge theories coupled to two flavors of fermions in the two-index symmetric representation by performing numerical simulations in SU(4). The beta function, defined and calculated via the…

High Energy Physics - Lattice · Physics 2013-05-30 Thomas DeGrand , Yigal Shamir , Benjamin Svetitsky

We review our recent results on the infrared behaviour of the SU(2) gauge theory with $N_f$ massless fundamental flavour fermions. We have analyzed the running of the coupling in SU(2) gauge theories with six and eight fermionic flavours…

High Energy Physics - Lattice · Physics 2018-12-03 Viljami Leino , Kari Rummukainen , Joni M. Suorsa , Kimmo Tuominen , Sara Tähtinen

We analyze the behavior of several renormalization group functions at infrared fixed points for $SU(N)$ gauge theories with fermions in the fundamental and two-indexed representations. This includes the beta function of the gauge coupling,…

High Energy Physics - Phenomenology · Physics 2014-03-18 Thomas A. Ryttov

We propose a novel RG method to specify the location of the IR fixed point in lattice gauge theories and apply it to the $SU(3)$ gauge theories with $N_f$ fundamental fermions. It is based on the scaling behavior of the propagator through…

High Energy Physics - Lattice · Physics 2015-07-21 K. -I. Ishikawa , Y. Iwasaki , Yu Nakayama , Y. Yoshie

We have carried out a Schrodinger-functional calculation for the Abelian gauge theory with Nf=2 four-component fermions in three dimensions. We find no fixed point in the beta function, meaning that the theory is confining rather than…

High Energy Physics - Lattice · Physics 2014-10-02 Benjamin Svetitsky , Ohad Raviv , Yigal Shamir

We present strong numerical evidence for the existence of an infrared fixed point in the renormalization group flow of the SU(3) gauge-fermion system with twelve massless fermions in the fundamental representation. Our numerical simulations…

High Energy Physics - Lattice · Physics 2024-03-14 Curtis Taylor Peterson , Anna Hasenfratz

We determine non-perturbatively a fixed-point (FP) action for fermions in the two-dimensional U(1) gauge (Schwinger) model. Our parameterization for the fermionic action has terms within a $7\times 7$ square on the lattice, using compact…

High Energy Physics - Lattice · Physics 2009-10-30 C. B. Lang , T. K. Pany

We have calculated the running coupling in SU(2), SU(3), and SU(4) gauge theories to see whether they have infrared fixed points. An infrared fixed point means no confinement: It means that the long-distance physics is conformal, without a…

High Energy Physics - Lattice · Physics 2013-01-10 Benjamin Svetitsky

Incorporated with twisted boundary condition, Polyakov loop correlators can give a definition of the renormalized coupling. We employ this scheme for the step scaling method (with step size s = 2) in the search of conformal fixed point of…

We present studies of the SU(2) gauge theory with 4, 6 and 10 fermion flavors. These models are expected to lie on both sides of the edge of the conformal window, where the theory has an infrared fixed point. We observe that the coupling…

High Energy Physics - Lattice · Physics 2012-10-17 Tuomas Karavirta , Kimmo tuominen , Jarno Rantaharju , Kari Rummukainen

SU(2) gauge theory with two fermions transforming under the adjoint representation may appear conformal or almost conformal in the infrared, and is one of the candidate theories for building models for technicolor. Early lattice Monte Carlo…

High Energy Physics - Lattice · Physics 2015-05-20 Tuomas Karavirta , Anne Mykkanen , Jarno Rantaharju , Kari Rummukainen , Kimmo Tuominen