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Related papers: Poisson statistics in the high temperature QCD Dir…

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We analyze the statistical properties of the spectrum of the QCD Dirac operator at low energy in a finite box of volume $L^4$ by means of partially quenched Chiral Perturbation Theory (pqChPT), a low-energy effective field theory based on…

High Energy Physics - Theory · Physics 2009-10-31 D. Toublan , J. J. M. Verbaarschot

In the epsilon-regime of QCD the main features of the spectrum of the low-lying eigenvalues of the (euclidean) Dirac operator are expected to be described by a certain universality class of random matrix models. In particular, the latter…

High Energy Physics - Lattice · Physics 2009-11-10 Leonardo Giusti , Martin Lüscher , Peter Weisz , Hartmut Wittig

In the $\varepsilon$-regime of chiral perturbation theory the spectral correlations of the Euclidean QCD Dirac operator close to the origin can be computed using random matrix theory. To incorporate the effect of temperature, a random…

Mathematical Physics · Physics 2022-01-05 Gernot Akemann , Tim R. Würfel

We analyze the smallest Dirac eigenvalues by formulating an effective theory for the QCD Dirac spectrum. We find that in a domain where the kinetic term of the effective theory can be ignored, the Dirac eigenvalues are distributed according…

High Energy Physics - Theory · Physics 2011-04-15 D. Toublan , J. J. M. Verbaarschot

We investigate the low-lying eigenmodes of the Dirac matrix with the aim to gain more insight into the temperature dependence of the anomalous $U_A(1)$ symmetry. We use the overlap operator to probe dynamical QCD configurations generated…

High Energy Physics - Lattice · Physics 2015-05-20 Viktor Dick , Frithjof Karsch , Edwin Laermann , Swagato Mukherjee , Sayantan Sharma

In this talk we review some recent results from random matrix models as applied to some non-perturbative issues in QCD. All of the issues we will discuss touched upon the important phenomenon related to the spontaneous breaking of chiral…

High Energy Physics - Phenomenology · Physics 2007-05-23 Romuald A. Janik , Maciej A. Nowak , Gabor Papp , Ismail Zahed

In this lecture we argue that the fluctuations of Dirac eigenvalues on the finest scale, i.e. on the scale of the average level spacing do not depend on the underlying dynamics and can be obtained from a chiral random matrix theory with the…

High Energy Physics - Lattice · Physics 2007-05-23 J. J. M. Verbaarschot

We study complete eigenvalue spectra of the staggered Dirac matrix in quenched QCD on a $6^3\times 4$ lattice. In particular, we investigate the nearest-neighbor spacing distribution $P(s)$ for various values of $\beta$ both in the…

High Energy Physics - Lattice · Physics 2009-10-30 H. Markum , R. Pullirsch , K. Rabitsch , T. Wettig

We study the eigenvalues of Dirac operators in QCD with two mass degenerate dynamical fermions. The gauge configurations have been obtained with HMC and the so-called Chirally Improved fermionic action. We compare eigenvalues obtained for…

High Energy Physics - Lattice · Physics 2009-04-14 Martina Joergler , C. B. Lang

We discuss the eigenvalue distribution of the overlap Dirac operator in quenched QCD on lattices of size 8^{4}, 10^{4} and 12^{4} at \beta = 5.85 and \beta = 6. We distinguish the topological sectors and study the distributions of the…

High Energy Physics - Lattice · Physics 2009-11-10 W. Bietenholz , K. Jansen , S. Shcheredin

We investigate the eigenvalue spectrum of the staggered Dirac matrix in two color QCD at finite chemical potential. The profiles of complex eigenvalues close to the origin are compared to a complex generalization of the chiral Gaussian…

High Energy Physics - Lattice · Physics 2008-11-26 Gernot Akemann , Elmar Bittner , Maria-Paola Lombardo , Harald Markum , Rainer Pullirsch

We study various improved staggered quark Dirac operators on quenched gluon backgrounds in lattice QCD. We find a clear separation of the spectrum of eigenvalues into high chirality, would-be zero modes and others, in accordance with the…

High Energy Physics - Lattice · Physics 2015-06-25 E. Follana , A. Hart , C. T. H. Davies

We compute the chiral condensate in 2+1-flavor QCD through the spectrum of low-lying eigenmodes of Dirac operator. The number of eigenvalues of the Dirac operator is evaluated using a stochastic method with an eigenvalue filtering technique…

High Energy Physics - Lattice · Physics 2016-08-22 Guido Cossu , Hidenori Fukaya , Shoji Hashimoto , Takashi Kaneko , Jun-Ichi Noaki

We compute the microscopic spectrum of the QCD Dirac operator in the presence of dynamical fermions in the framework of random-matrix theory for the chiral Gaussian unitary ensemble. We obtain results for the microscopic spectral…

High Energy Physics - Theory · Physics 2009-10-30 T. Wilke , T. Guhr , T. Wettig

We investigate and clarify the role of topology and the issues surrounding the epsilon regime for staggered quarks. We study unimproved and improved staggered quark Dirac operators on quenched lattice QCD gluon backgrounds generated using a…

High Energy Physics - Lattice · Physics 2009-11-11 E. Follana , A. Hart , C. T. H. Davies , Q. Mason

We review the present status of the Anderson transition in the spectrum of the Dirac operator of QCD-like theories on the lattice. Localized modes at the low-end of the spectrum have been found in SU(2) Yang-Mills theory with overlap and…

High Energy Physics - Lattice · Physics 2015-06-22 Matteo Giordano , Tamas G. Kovacs , Ferenc Pittler

In the first part of these lectures we discuss the infrared limit of the spectrum of the QCD Dirac operator. We discuss the global symmetries of the QCD partition function and show that the Dirac spectrum near zero virtuality is determined…

High Energy Physics - Phenomenology · Physics 2007-05-23 J. J. M. Verbaarschot

We have computed ensembles of complete spectra of the staggered Dirac operator using four-dimensional SU(2) gauge fields, both in the quenched approximation and with dynamical fermions. To identify universal features in the Dirac spectrum,…

High Energy Physics - Lattice · Physics 2009-10-31 M. E. Berbenni-Bitsch , M. Göckeler , S. Meyer , A. Schäfer , T. Wettig

Recently we found an Anderson-type localization-delocalization transition in the QCD Dirac spectrum at high temperature. Using spectral statistics we obtained a critical exponent compatible with that of the corresponding Anderson model.…

High Energy Physics - Lattice · Physics 2014-10-31 Matteo Giordano , Tamas G. Kovacs , Ferenc Pittler , Laszlo Ujfalusi , Imre Varga

The microscopic spectral eigenvalue correlations of QCD Dirac operators in the presence of dynamical fermions are calculated within the framework of Random Matrix Theory (RMT). Our approach treats the low--energy correlation functions of…

High Energy Physics - Lattice · Physics 2008-11-26 G. Akemann , E. Kanzieper