English
Related papers

Related papers: Dirac Spectrum in Adjoint QCD

200 papers

A chiral fermion action allows one to do very clean studies of chiral symmetry breaking in QCD. I will briefly describe how to compute with the overlap action (relatively) cheaply, and then turn to physics: Low modes of the Dirac operator…

High Energy Physics - Lattice · Physics 2007-05-23 Thomas DeGrand

In this talk we discuss the microscopic limit of QCD at nonzero chemical potential. In this domain, where the QCD partition function is under complete analytical control, we uncover an entirely new link between the spectral density of the…

High Energy Physics - Lattice · Physics 2017-08-23 J. C. Osborn , K. Splittorff , J. J. M. Verbaarschot

We compute the Dirac spectral density of QCD in a wide range of eigenvalues by using a stochastic method. We use 2+1 flavor lattice ensembles generated with Mobius domain-wall fermion at three lattice spacings ($a=0.083, 0.055, 0.044$ fm)…

High Energy Physics - Lattice · Physics 2018-04-18 Katsumasa Nakayama , Shoji Hashimoto , Hidenori Fukaya

We analyze the mass dependence of the chiral condensate for QCD at nonzero $\theta$-angle and find that in general the discontinuity of the chiral condensate is not on the support of the Dirac spectrum. To understand this behavior we…

High Energy Physics - Theory · Physics 2019-05-08 M. Kieburg , J. J. M. Verbaarschot , T. Wettig

At low temperature in the epsilon regime of QCD the low-end of the Dirac spectrum is described by random matrix theory. In contrast, there has been no similarly well established staistical description in the high temperature, chirally…

High Energy Physics - Lattice · Physics 2010-11-16 Tamas G. Kovacs , Ferenc Pittler

The lowest eigenmodes of the Dirac operator are related to the dynamical breaking of the chiral symmetry in Quantum Chromodynamics (QCD). In our work we construct quark propagators which exclude a varying number of the lowest Dirac…

High Energy Physics - Lattice · Physics 2011-11-22 C. B. Lang , Mario Schröck

We compute the low lying spectrum of the overlap Dirac operator in the deconfined phase of finite-temperature quenched gauge theory. It suggests the existence of a chiral condensate which we confirm with a direct stochastic estimate. We…

High Energy Physics - Lattice · Physics 2014-11-17 Robert G. Edwards , Urs M. Heller , Joe Kiskis , Rajamani Narayanan

The zero momentum sectors in effective theories of QCD coupled to pseudoreal (two colors) and real (adjoint) quarks have alternative descriptions in terms of chiral orthogonal and symplectic ensembles of random matrices. Using this…

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

The low-lying spectrum of the Dirac operator is predicted to be universal, within three classes, depending on symmetry properties specified according to random matrix theory. The three universal classes are the orthogonal, unitary and…

High Energy Physics - Lattice · Physics 2009-10-31 Robert G. Edwards , Urs M. Heller , Rajamani Narayanan

We analyze Dirac spectra of two-dimensional QCD like theories both in the continuum and on the lattice and classify them according to random matrix theories sharing the same global symmetries. The classification is different from QCD in…

High Energy Physics - Lattice · Physics 2014-10-22 Mario Kieburg , Jacobus J. M. Verbaarschot , Savvas Zafeiropoulos

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 argue that the spectrum of the QCD Dirac operator near zero virtuality can be described by random matrix theory. As in the case of classical random matrix ensembles of Dyson we have three distinct classes: the chiral orthogonal ensemble…

High Energy Physics - Theory · Physics 2011-07-18 Jacobus Verbaarschot

We compare the low-lying spectrum of the staggered Dirac operator in the confining phase of compact U(1) gauge theory on the lattice to predictions of chiral random matrix theory. The small eigenvalues contribute to the chiral condensate…

High Energy Physics - Lattice · Physics 2009-10-31 B. A. Berg , H. Markum , R. Pullirsch , T. Wettig

We introduce Random Matrix Models for the Hermitian Wilson-Dirac operator of QCD-like theories. We show that they are equivalent to the $\epsilon$-limit of the chiral Lagrangian for Wilson chiral perturbation theory. Results are obtained…

High Energy Physics - Lattice · Physics 2013-03-14 Mario Kieburg , Jacobus J. M. Verbaarschot , Savvas Zafeiropoulos

We study the behavior of the spectrum of the Dirac operator on degenerating families of compact Riemannian surfaces, when the length $t$ of a simple closed geodesic shrinks to zero, under the hypothesis that the spin structure along the…

Differential Geometry · Mathematics 2024-09-10 Cipriana Anghel

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 use the graded eigenvalue method, a variant of the supersymmetry technique, to compute the universal spectral correlations of the QCD Dirac operator in the presence of massive dynamical quarks. The calculation is done for the chiral…

High Energy Physics - Theory · Physics 2009-10-31 Burkhard Seif , Tilo Wettig , Thomas Guhr

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

We investigate the eigenvalue spectrum of the staggered Dirac matrix in SU(3) and U(1) gauge theory as well as in full QCD with two colors and finite chemical potential. Along the strong-coupling axis up to the phase transition, the…

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

The distribution of the low-lying QCD Dirac spectrum is analyzed by means of partial quenched chiral perturbation theory. We identify an energy scale below which the valence quark mass dependence of the QCD partition function is given by…

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