English
Related papers

Related papers: Anomalous Dimension in QCD

200 papers

In this work we present the results of our investigation of \su{2} gauge theory with two Dirac fermions in the adjoint representation (aQCD2), which belongs to the class of strongly interacting gauge theories that are of basic interest for…

High Energy Physics - Lattice · Physics 2022-09-13 Georg Bergner , Pietro Giudice , Istvan Montvay , Gernot Münster , Stefano Piemonte

Graphene is a monolayer of carbon atoms packed into a hexagon lattice to host two pairs of massless two-dimensional Dirac fermions in the absence of or with negligible spin-orbit coupling. It is known that the existence of non-zero electric…

Mesoscale and Nanoscale Physics · Physics 2017-07-27 Shun-Qing Shen , Chang-An Li , Qian Niu

In the domain wall fermion formulation, chiral symmetry breaking in full QCD is expected to fall exponentially with the length of the extra dimension. We measure the chiral symmetry breaking due to a finite extra dimension in two ways,…

High Energy Physics - Lattice · Physics 2015-06-25 George R. Fleming

We compute anomalous dimensions of quartic operators which are singlets under the $\mathrm{U}(N_f)$ global symmetry in Yang-Mills theories with Chern-Simons level $k$ in three dimensions coupled to $N_f$ Dirac fermions. In order to have…

High Energy Physics - Theory · Physics 2022-12-09 Guillermo Arias-Tamargo , Sergio Benvenuti , Diego Rodriguez-Gomez

This article gives details of our proposal to replace ordinary chiral $SU(3)_L\times SU(3)_R$ perturbation theory $\chi$PT$_3$ by 3-flavor chiral-scale perturbation theory $\chi$PT$_\sigma$. In $\chi$PT$_\sigma$, amplitudes are expanded at…

High Energy Physics - Phenomenology · Physics 2015-02-25 R. J. Crewther , Lewis C. Tunstall

A strategy for computing the psibar-psi anomalous dimension at the fixed point in infrared-conformal gauge theories from lattice simulations is discussed. The method is based on the scaling of the spectral density of the Dirac operator or…

High Energy Physics - Lattice · Physics 2012-08-20 Agostino Patella

We consider the chiral anomaly for systems with a wide class of Hermitian Dirac operators ${Q}$ in 4D Euclidean spacetime. We suppose that $ Q$ is not necessarily linear in derivatives and also that it contains a coordinate inhomogeneity…

High Energy Physics - Theory · Physics 2025-11-26 Praveen D. Xavier , M. A. Zubkov

In QCD with 16\half-epsilon massless quark flavours there is an infrared fixed point with alpha_s/pi = (8/321)epsilon in the limit epsilon -> 0+. I develop the idea of Banks and Zaks to expand about N_f=16\half. This expansion is certainly…

High Energy Physics - Phenomenology · Physics 2009-10-28 P. M. Stevenson

Operator product expansions are applied to dilaton-axion four-point functions. In the expansions of the bilocal fields $\tilde{\Phi}\tilde{\Phi}$, $\tilde{C}\tilde{C}$ and $\tilde{\Phi}\tilde{C}$, the conformal fields which are symmetric…

High Energy Physics - Theory · Physics 2009-10-31 L. Hoffmann , L. Mesref , W. Ruehl

The infrared divergences of massless n-parton scattering amplitudes can be derived from the anomalous dimension of n-jet operators in soft-collinear effective theory. Up to three-loop order, the latter has been shown to have a very simple…

High Energy Physics - Phenomenology · Physics 2015-06-11 Valentin Ahrens , Matthias Neubert , Leonardo Vernazza

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

Quenched QCD simulations on three volumes, $8^3 \times$, $12^3 \times$ and $16^3 \times 32$ and three couplings, $\beta=5.7$, 5.85 and 6.0 using domain wall fermions provide a consistent picture of quenched QCD. We demonstrate that the…

The chiral anomaly is a quantum mechanical effect for massless Dirac fermions in both particle physics and condensed matter physics. Here we present a set of effective models for single massless Dirac fermions in one- and three-dimensions…

Mesoscale and Nanoscale Physics · Physics 2025-09-11 Huan-Wen Wang , Bo Fu , Shun-Qing Shen

A possible formulation of chiral gauge theories with an anomalous fermion content is re-examined in light of the lattice framework based on the Ginsparg-Wilson relation. It is shown that the fermion sector of a wide class of anomalous…

High Energy Physics - Lattice · Physics 2009-11-10 Kosuke Matsui , Hiroshi Suzuki

We study duality in $\mathcal{N}=1$ supersymmetric QCD in the non-Abelian Coulomb phase, order-by-order in scheme-independent series expansions. Using exact results, we show how the dimensions of various fundamental and composite chiral…

High Energy Physics - Theory · Physics 2018-04-04 Thomas A. Ryttov , Robert Shrock

Some years ago Anton Yu. Alekseev et al. conjectured the existence of massless modes in the spectrum of excitations ("anomalous massless modes") building upon certain similarities between a spontaneous symmetry breaking and the interplay of…

High Energy Physics - Theory · Physics 2014-12-05 Luis Melgar

We devise a geometric description of bounded systems at criticality in any dimension $d$. This is achieved by altering the flat metric with a space dependent scale factor $\gamma(x)$, $x$ belonging to a general bounded domain $\Omega$.…

Statistical Mechanics · Physics 2020-07-09 Giacomo Gori , Andrea Trombettoni

There is evidence for existence of massless Dirac quasi-particles in graphene, which satisfy Dirac equation in (1+2) dimensions near the so called Dirac points which lie at the corners at the graphene's brilluoin zone. It is shown that…

Mesoscale and Nanoscale Physics · Physics 2011-05-31 Riazuddin

We formulate the three dimensional Thirring model on a spacetime lattice and study it for various even numbers of fermion flavors N_f by Monte Carlo simulation. We find clear evidence for spontaneous chiral symmetry breaking at strong…

High Energy Physics - Lattice · Physics 2009-10-30 L. Del Debbio , S. J. Hands , J. C. Mehegan

The gamma -> 3 pi form factor was calculated in a simple-minded constituent model with a constant quark mass parameter, as well as in the Schwinger-Dyson approach. The comparison of these and various other theoretical results on this…

High Energy Physics - Phenomenology · Physics 2007-05-23 Dubravko Klabucar , Bojan Bistrovic