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Related papers: Conformal window from conformal expansion

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The slowly evolving gauge coupling of gauge-fermion systems near the conformal window makes numerical investigations of these models challenging. We consider finite size scaling and show that this often used technique leads to inconsistent…

High Energy Physics - Lattice · Physics 2014-07-30 Anqi Cheng , Anna Hasenfratz , Yuzhi Liu , Gregory Petropoulos , David Schaich

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

{We present the results of a numerical investigation of SU(2) gauge theory with $N_f=3/2$ flavours of fermions, corresponding to 3 Majorana fermions, which transform in the adjoint representation of the gauge group. At two values of the…

High Energy Physics - Lattice · Physics 2018-11-12 Georg Bergner , Pietro Giudice , Istvan Montvay , Gernot Münster , Stefano Piemonte , Philipp Scior

We compute the nonzero temperature free energy up to the order g^6 \ln(1/g) in the coupling constant for vector like SU(N) gauge theories featuring matter transforming according to different representations of the underlying gauge group.…

High Energy Physics - Phenomenology · Physics 2011-03-07 Matin Mojaza , Claudio Pica , Francesco Sannino

For all the success of the Standard Model (SM), it is on the verge of being surpassed. In this regard we argue, by showing a minimal flavor-structured model based on the non-Abelian discrete $SL_2(F_3)$ symmetry, that $U(1)$…

High Energy Physics - Phenomenology · Physics 2019-02-20 Y. H. Ahn

We present a brief overview of our recent lattice studies of SU(3) gauge theory with N_f = 8 and 12 fundamental fermions, including some new and yet-unpublished results. To explore relatively unfamiliar systems beyond lattice QCD, we carry…

High Energy Physics - Lattice · Physics 2017-08-23 Anna Hasenfratz , Anqi Cheng , Gregory Petropoulos , David Schaich

We study the SU(3) gauge theory with Nf=12 flavors in the fundamental representation by use of lattice simulations with staggered fermions. With a non-improved action we observe a chiral zero-temperature (bulk) transition separating a…

High Energy Physics - Lattice · Physics 2013-03-26 Albert Deuzeman , Maria Paola Lombardo , Tiago Nunes da Silva , Elisabetta Pallante

We present our lattice studies of SU(3) gauge theory with $N_f$ = 8 degenerate fermions in the fundamental representation. Using nHYP-smeared staggered fermions we study finite-temperature transitions on lattice volumes as large as $L^3…

We consider a vectorial, asymptotically free SU($N_c$) gauge theory with $N_f$ fermions in a representation $R$ having an infrared (IR) fixed point. We calculate and analyze Pad\'e approximants to scheme-independent series expansions for…

High Energy Physics - Theory · Physics 2018-01-17 Thomas A. Ryttov , Robert Shrock

We study the alignment of the vacuum in gauge theories with $N_f$ Dirac fermions transforming according to a complex representation of the gauge group. The alignment of the vacuum is produced by adding a small mass perturbation to the…

High Energy Physics - Phenomenology · Physics 2014-06-06 Thomas A. Ryttov

We study asymptotically free chiral gauge theories with an SU($N$) gauge group and chiral fermions transforming according to the antisymmetric rank-$k$ tensor representation, $A_k \equiv [k]_N$, and the requisite number, $n_{\bar F}$, of…

High Energy Physics - Theory · Physics 2015-12-02 Yan-Liang Shi , Robert Shrock

We present updated results for the non-perturbative $\beta$-function of SU(3) gauge theories with $N_f = 12$ or 10 massless flavors in the fundamental rep or $N_f = 2$ in the sextet rep, measured with staggered fermions. New data at finer…

High Energy Physics - Lattice · Physics 2019-12-18 Zoltan Fodor , Kieran Holland , Julius Kuti , Daniel Nogradi , Chik Him Wong

We determine the anomalous dimensions of baryon operators for the three color theory as function of the number of massless flavours within the conformal window to the maximum known order in perturbation theory. We show that the anomalous…

High Energy Physics - Phenomenology · Physics 2016-11-15 Claudio Pica , Francesco Sannino

We investigate the phase structure of Quantum Chromodynamics (QCD) in the vacuum as a function of quark flavor number $N_f$ within the chiral limit. By self-consistently solving the coupled DSEs for the quark and gluon propagators in a…

High Energy Physics - Phenomenology · Physics 2026-02-19 Yi-huai Chen , Yi Lu , Zhi-wei Wang , Yu-xin Liu , Fei Gao

We use Monte Carlo simulation to probe the phase structure of a SU(2) gauge theory containing $N_f$ Dirac fermion flavors transforming in the fundamental representation of the group and interacting through an additional four fermion term.…

High Energy Physics - Lattice · Physics 2013-05-30 Simon Catterall , Richard Galvez , Jay Hubisz , Dhagash Mehta , Aarti Veernala

We investigate the eigenmodes of the massless Dirac operator to extract the scale-dependent fermion mass anomalous dimension gamma_m(mu). By combining simulations on multiple lattice volumes, and when possible several gauge couplings, we…

High Energy Physics - Lattice · Physics 2013-07-16 Anqi Cheng , Anna Hasenfratz , Gregory Petropoulos , David Schaich

When the number of massless fermions exceeds a critical value $N_f^*$, QCD enters the conformal window and becomes chirally symmetric already in the vacuum. Determining $N_f^*$ from lattice simulations is challenging, since calculations are…

High Energy Physics - Lattice · Physics 2026-03-23 Jan Philipp Klinger , Reinhold Kaiser , Owe Philipsen , Jonas Schaible

We investigate the finite-temperature and -density chiral Gross-Neveu model with an axial U$_A$(1) symmetry in $1+1$ dimensions on the lattice. In the limit where the number of flavors $N_\mathrm{f}$ tends to infinity the continuum model…

High Energy Physics - Lattice · Physics 2022-03-03 Julian J. Lenz , Michael Mandl , Andreas Wipf

We study the strong-interaction dynamics of a class of $4D$ chiral $SU(N)$ gauge theories with a fermion in a symmetric second-rank tensor representation and a number of fermions in an anti-antisymmetric tensor representation, extending the…

High Energy Physics - Theory · Physics 2025-02-04 Stefano Bolognesi , Kenichi Konishi , Andrea Luzio , Matteo Orso

We study the chiral condensate $<\bar{\psi} \psi>$ for an SU(3) gauge theory with $N_f$ massless Dirac fermions in the fundamental representation when $N_f$ is increased from 2 to 6. For $N_f=2$, our lattice simulations of $<\bar{\psi} \psi…