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Related papers: Distribution of the Dirac modes in QCD

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We investigate the effects of low-lying fermion eigenmodes on the QCD partition function in the $\epsilon$-regime. The fermion determinant is approximated by a truncated product of low-lying eigenvalues of the overlap-Dirac operator. With…

High Energy Physics - Lattice · Physics 2009-11-11 Kenji Ogawa , Shoji Hashimoto

In a deep-infrared (ergodic) regime, QCD coupled to massive pseudoreal and real quarks are described by chiral orthogonal and symplectic ensembles of random matrices. Using this correspondence, general expressions for the QCD partition…

High Energy Physics - Theory · Physics 2009-10-31 T. Nagao , S. M. Nishigaki

The supersymmetric method is a powerful method for the evaluation of quenched averages in disordered systems. Among others, this method has been applied to the theory of S-matrix fluctuations, the theory of universal conductance…

High Energy Physics - Theory · Physics 2009-11-10 J. J. M. Verbaarschot

We use a chiral random matrix model with 2N_f flavors to mock up the QCD Dirac spectrum at finite chemical potential. We show that the 1/N approximation breaks down in the quenched state with spontaneously broken chiral symmetry. The…

High Energy Physics - Phenomenology · Physics 2016-08-15 Romuald A. Janik , Maciej A. Nowak , Gábor Papp , Ismail Zahed

The lattice studies in QCD demonstrate the nontrivial localization behavior of the eigenmodes of the 4D Euclidean Dirac operator considered as Hamiltonian of $4+1$ dimensional disordered system. We use the holographic viewpoint to provide…

High Energy Physics - Theory · Physics 2019-07-04 A. Gorsky , M. Litvinov

We investigate the eigenvalue spectrum of the staggered Dirac matrix in SU(3) gauge theory and in full QCD as well as in quenched U(1) theory on various lattice sizes. As a measure of the fluctuation properties of the eigenvalues, we…

High Energy Physics - Lattice · Physics 2007-05-23 B. A. Berg , E. Bittner , M. -P. Lombardo , H. Markum , R. Pullirsch , T. Wettig

We study the spectrum of the QCD Dirac operator near zero virtuality for $N_c =2$. According to a universality argument, it can be described by a random matrix theory with the chiral structure of QCD, but with $real$ matrix elements. Using…

High Energy Physics - Theory · Physics 2009-10-28 Jacobus Verbaarschot

Based on the exact relationship to random matrix theory, we present an alternative method of evaluating the probability distribution of the k-th smallest Dirac eigenvalue in the epsilon-regime of QCD and QCD-like theories. By utilizing the…

High Energy Physics - Lattice · Physics 2016-07-13 Shinsuke M. Nishigaki

We analyze the eigenvalue spectrum of the staggered Dirac matrix in two-color QCD at nonzero baryon density when the eigenvalues become complex. The quasi-zero modes and their role for chiral symmetry breaking and the deconfinement…

High Energy Physics - Lattice · Physics 2009-10-31 Elmar Bittner , Maria-Paola Lombardo , Harald Markum , Rainer Pullirsch

We investigate the QCD Dirac operator with gauge configurations given by a liquid of instantons in the region of temperatures about the chiral phase transition. Both the quenched and unquenched cases are examined in detail. We present…

High Energy Physics - Phenomenology · Physics 2008-11-26 Antonio M. Garcia-Garcia , James C. Osborn

We briefly review the overlap formalism for chiral gauge theories, the overlap Dirac operator for massless fermions and its connection to domain wall fermions. We describe properties of the overlap Dirac operator, and methods to implement…

High Energy Physics - Lattice · Physics 2007-05-23 Robert G. Edwards , Urs M. Heller , Joe Kiskis , Rajamani Narayanan

We study the low eigenmodes of the overlap and staggered Dirac operator at high temperature. We show that the recently found localized quark modes obeying Poisson statistics are connected to physical gauge field objects with their size and…

High Energy Physics - Lattice · Physics 2011-12-02 Tamas G. Kovacs , Ferenc Pittler , Falk Bruckmann , Sebastian Schierenberg

We study spontaneous chiral symmetry breaking and the spectral properties of the staggered lattice Dirac operator using quenched gauge configurations for the exceptional group G2, which has a trivial center. In particular we study the…

High Energy Physics - Lattice · Physics 2009-01-16 Julia Danzer , Christof Gattringer , Axel Maas

Quasi-one-dimensional stochastic Dirac operators with an odd number of channels, time reversal symmetry but otherwise efficiently coupled randomness are shown to have one conducting channel and absolutely continuous spectrum of multiplicity…

Mathematical Physics · Physics 2011-01-25 Christian Sadel , Hermann Schulz-Baldes

We address the question of whether the low modes of the Dirac operator are caused by topological objects such as instantons in SU(N) gauge theories. We study the pseudo-scalar density of these modes, finding the size distributions of the…

High Energy Physics - Lattice · Physics 2009-11-07 N. Cundy , M. Teper , U. Wenger

We investigate the eigenvalue spectrum of the staggered Dirac matrix in SU(3) gauge theory and in full QCD on a $6^3\times 4$ lattice. As a measure of the fluctuation properties of the eigenvalues, we study the nearest-neighbor spacing…

High Energy Physics - Phenomenology · Physics 2009-10-31 R. Pullirsch , K. Rabitsch , T. Wettig , H. Markum

We apply a complex chiral random matrix model as an effective model to QCD with a small chemical potential at zero temperature. In our model the correlation functions of complex eigenvalues can be determined analytically in two different…

High Energy Physics - Lattice · Physics 2017-08-23 G. Akemann , T. Wettig

We present simulation results for lattice QCD with light pions. For the quark fields we apply chirally symmetric lattice Dirac operators, in particular the overlap hypercube operator, along with the standard overlap operator for comparison.…

High Energy Physics - Lattice · Physics 2007-05-23 W. Bietenholz , S. Shcheredin

We investigate spontaneous chiral symmetry breaking in SU(N) gauge theories at large N using overlap fermions. The exact zero modes and the low-lying modes of the Dirac operator provide the tools to gain insight into the interplay between…

High Energy Physics - Lattice · Physics 2009-11-10 N. Cundy , M. Teper , U. Wenger

We propose a new way of understanding how chiral symmetry is realized in the high temperature phase of QCD. Based on the finding that a simple free instanton gas precisely describes the details of the lowest part of the spectrum of the…

High Energy Physics - Lattice · Physics 2024-05-24 Tamas G. Kovacs