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Related papers: Running coupling in SU(2) with adjoint fermions

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We study SU(2) lattice gauge theory with two flavours of Dirac fermions in the adjoint representation. We measure the running of the coupling in the Schroedinger Functional (SF) scheme and find it is consistent with existing results. We…

High Energy Physics - Phenomenology · Physics 2010-04-06 Francis Bursa , Luigi Del Debbio , Liam Keegan , Claudio Pica , Thomas Pickup

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 present a Monte Carlo renormalisation group study of the SU(2) gauge theory with two Dirac fermions in the adjoint representation. Using the two lattice matching technique recently advocated and exploited in [arXiv:0907.0919], we measure…

High Energy Physics - Phenomenology · Physics 2011-03-18 Simon Catterall , Luigi Del Debbio , Joel Giedt , Liam Keegan

A non perturbative finite size scaling technique is used to study a running coupling in lattice Yang-Mills theory coupled to a bosonic Wilson spinor field in the Schr\"odinger functional scheme. This corresponds to two negative flavours.…

High Energy Physics - Lattice · Physics 2015-06-25 Juri Rolf , Ulli Wolff

In pure SU(2) gauge theory we compute the two-loop coefficient in the relation between the lattice bare coupling and the running coupling defined through the Schroedinger functional. This result is required to relate the latter to the…

High Energy Physics - Lattice · Physics 2009-10-22 Ulli Wolff

We discuss the setup and features of a new definition of the running coupling in the Schr\"odinger functional scheme based on the gradient flow. Its suitability for a precise continuum limit in QCD is demonstrated on a set of Nf=2 gauge…

High Energy Physics - Lattice · Physics 2015-06-16 Patrick Fritzsch , Alberto Ramos

The Yang-Mills gradient flow in finite volume is used to define a running coupling scheme. As our main result the discrete beta-function, or step scaling function, is calculated for scale change s=3/2 at several lattice spacings for SU(3)…

High Energy Physics - Lattice · Physics 2012-11-15 Zoltan Fodor , Kieran Holland , Julius Kuti , Daniel Nogradi , Chik Him Wong

We have carried out a Schrodinger functional (SF) calculation for the SU(3) lattice gauge theory with two flavors of Wilson fermions in the sextet representation of the gauge group. We find that the discrete beta function, which governs the…

High Energy Physics - Lattice · Physics 2008-11-26 Yigal Shamir , Benjamin Svetitsky , Thomas DeGrand

The lattice phase structure of a gauge theory can be a serious obstruction to Monte Carlo studies of its continuum behaviour. This issue is particularly delicate when numerical studies are performed to determine whether a theory is in a…

High Energy Physics - Lattice · Physics 2014-08-14 Biagio Lucini , Agostino Patella , Antonio Rago , Enrico Rinaldi

We discuss the Schr\"odinger functional in lattice QCD with staggered fermions and relate it, in the classical continuum limit, to the Schr\"odinger functional regularized with Wilson fermions. We compute the strong coupling constant…

High Energy Physics - Lattice · Physics 2009-10-30 Urs M. Heller

We present our preliminary study of the SU(2) gauge theory with 8 flavors of fermions in fundamental representation. This theory could be a candidate of the gauge theory with conformal fixed point. By using Wilson/Polyakov loop in a finite…

We simulate $ SU(2) $ lattice gauge theory using dynamical reduced staggered fermions. The latter lead to two rather than four Dirac fermions in the continuum limit. We review the derivation and properties of reduced staggered fermions and…

High Energy Physics - Lattice · Physics 2019-01-23 Simon Catterall , Nouman Butt

The scaling of the Schr"odinger functional coupling is studied numerically and perturbatively for an SU(3) lattice gauge field coupled to an O(a) improved bosonic spinor field. This corresponds to QCD with minus two light flavours and is…

High Energy Physics - Lattice · Physics 2015-06-25 Bernd Gehrmann , Juri Rolf , Stefan Kurth , Ulli Wolff

We present the updated results of the infrared behavior of the SU(2) 6 and 8 fundamental representation fermions. We use the gradient flow method with the Schr\"odinger functional boundary conditions to measure the running of the coupling…

High Energy Physics - Lattice · Physics 2018-04-18 Viljami Leino , Jarno Rantaharju , Teemu Rantalaiho , Kari Rummukainen , Joni M. Suorsa , Kimmo Tuominen , Sara Tähtinen

The standard method to calculate non-perturbatively the evolution of the running coupling of a SU(N) gauge theory is based on the Schr\"odinger functional (SF). In this paper we construct a family of boundary fields for general values of N…

High Energy Physics - Lattice · Physics 2015-06-22 Ari Hietanen , Tuomas Karavirta , Pol Vilaseca

We study the dynamics of SU(2) gauge theory with NF=6 Dirac fermions by means of lattice simulation to investigate if they are appropriate to realization of electroweak symmetry breaking. The discrete analogue of beta function for the…

High Energy Physics - Lattice · Physics 2012-10-19 M. Hayakawa , K. -I. Ishikawa , Y. Osaki , S. Takeda , N. Yamada

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

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 compute the two loop coefficient in the relation between the lattice bare coupling and the running coupling defined through the Schroedinger functional for the case of pure SU(2) gauge theory. This result is needed as one computational…

High Energy Physics - Lattice · Physics 2016-08-31 Rajamani Narayanan , Ulli Wolff

The running of the coupling is studied in SU(4) gauge theory using the Schr\"odinger functional technique. Up to energies of the order of the square root of the string tension $\sigma$, the running is found to agree with the two-loop…

High Energy Physics - Lattice · Physics 2010-05-12 Biagio Lucini , Gregory Moraitis