English
Related papers

Related papers: Dirac eigenvalue correlations in quenched QCD at f…

200 papers

Two different matrix models for QCD with a non-vanishing quark chemical potential are shown to be equivalent by mapping the corresponding partition functions. The equivalence holds in the phase with broken chiral symmetry. It is exact in…

High Energy Physics - Theory · Physics 2007-05-23 G. Akemann

We present simulation results for lattice QCD with chiral fermions in small volumes, where the epsilon-expansion of chiral perturbation theory applies. Our data for the low lying Dirac eigenvalues, as well as mesonic correlation functions,…

High Energy Physics - Lattice · Physics 2009-11-11 W. Bietenholz , T. Chiarappa , K. Jansen , K. -I. Nagai , S. Shcheredin

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

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 prove that QCD in the epsilon-regime of chiral Perturbation Theory is equivalent to chiral Random Matrix Theory for zero and both non-zero real and imaginary chemical potential mu. To this aim we prove a theorem that relates integrals…

High Energy Physics - Theory · Physics 2008-11-26 Francesco Basile , Gernot Akemann

We calculate the low-lying eigenmodes of the Neuberger overlap-Dirac operator for $4d$ compact lattice QED in the quenched approximation. In the strong coupling phase we find exact zero-modes, quite similar as in non-Abelian lattice QCD.…

High Energy Physics - Lattice · Physics 2009-11-07 Bernd A. Berg , Urs M. Heller , Harald Markum , Rainer Pullirsch , Wolfgang Sakuler

We calculate the response of the microscopic Dirac spectrum to an imaginary isospin chemical potential for QCD with two dynamical flavors in the chiral limit. This extends our previous calculation from the quenched to the unquenched theory.…

High Energy Physics - Lattice · Physics 2009-11-11 P. H. Damgaard , U. M. Heller , K. Splittorff , B. Svetitsky , D. Toublan

We calculate the spectral density of the Dirac operator over an ensemble of configurations composed of overlapping instantons and anti-instantons. We find evidence that the spectral density diverges in the limit of small eigenvalues. This…

High Energy Physics - Lattice · Physics 2009-10-31 U. Sharan , M. Teper

We show how to introduce a quark chemical potential in the overlap Dirac operator. The resulting operator satisfies a Ginsparg-Wilson relation and has exact zero modes. It is no longer gamma_5-hermitian, but its nonreal eigenvalues still…

High Energy Physics - Lattice · Physics 2009-01-14 Jacques Bloch , Tilo Wettig

The relation between the spectral density of the QCD Dirac operator at nonzero baryon chemical potential and the chiral condensate is investigated. We use the analytical result for the eigenvalue density in the microscopic regime which…

High Energy Physics - Theory · Physics 2009-11-11 J. C. Osborn , K. Splittorff , J. J. M. Verbaarschot

We study localization and chirality properties of eigenvectors of the lattice Dirac operator. In particular we focus on the dependence of our observables on the size of the corresponding eigenvalue, which allows us to study the transition…

High Energy Physics - Lattice · Physics 2008-11-26 Christof Gattringer , Meinulf Goeckeler , P. E. L. Rakow , Stefan Schaefer , Andreas Schaefer

We study lattice QCD in the limit that the quark mass and chemical potential are simultaneously made large, resulting in a controllable density of quarks which do not move; this is similar in spirit to the quenched approximation for zero…

High Energy Physics - Lattice · Physics 2007-05-23 T. Blum , J. E. Hetrick , D. Toussaint

The low-lying eigenvalue spectrum of the QCD Dirac operator in the epsilon-regime is expected to match with that of chiral Random Matrix Theory (ChRMT). We study this correspondence for the case including sea quarks by performing two-flavor…

High Energy Physics - Lattice · Physics 2012-08-27 JLQCD , TWQCD collaboration , : , H. Fukaya , S. Aoki , T. W. Chiu , S. Hashimoto , T. Kaneko , H. Matsufuru , J. Noaki , K. Ogawa , T. Onogi , N. Yamada

We report on the behavior of the eigenvalue distribution of the Dirac operator in (2+1)-flavor QCD at finite temperature, using the HISQ action. We calculate the eigenvalue density at several values of the temperature close to the…

High Energy Physics - Lattice · Physics 2012-02-21 H. Ohno , U. M. Heller , F. Karsch , S. Mukherjee

We discuss some properties of zero and near-zero modes of the Dirac operator, as observed in a recent simulation of 2-flavor QCD. The quarks have been implemented with the so-called Chirally Improved Dirac operator, which obeys the…

High Energy Physics - Lattice · Physics 2007-05-23 C. B. Lang , Pushan Majumdar , Wolfgang Ortner

We study lattice QCD in the limit that the quark mass and chemical potential are simultaneously made large, resulting in a controllable density of quarks which do not move. This is similar in spirit to the quenched approximation for zero…

High Energy Physics - Lattice · Physics 2009-10-28 Thomas C. Blum , James E. Hetrick , Doug Toussaint

We study the interplay of quark number density and chiral symmetry in lattice QCD. We suggest that both are controlled by the eigenvalue spectrum of the fermionic propagator matrix, which shapes the pattern of zeros of the partition…

High Energy Physics - Lattice · Physics 2007-05-23 M. -P. Lombardo

We study quenched QCD at finite chemical potential, $\mu_I$, for the third component of isospin and quenched two-colour QCD at finite chemical potential, $\mu$, for quark number. In contrast to the quenched approximation to QCD at finite…

High Energy Physics - Lattice · Physics 2009-11-07 J. B. Kogut , D. K. Sinclair

A brief summary of the formulation of QCD at finite chemical potental, $\mu$, is presented. The failure of the quenched approximation to the problem is reviewed. Results are presented for dynamical simulations of the theory at strong and…

High Energy Physics - Lattice · Physics 2009-10-30 I. M. Barbour , S. E. Morrison , E. G. Klepfish , J. B. Kogut , M. -P. Lombardo

We analyze the eigenvalues and eigenvectors of the staggered Dirac operator in quenched lattice QCD in the vicinity of the deconfinement phase transition using the L\"uscher-Weisz gauge action. The spectral and localization properties of…

High Energy Physics - Lattice · Physics 2008-11-26 C. Gattringer , M. Göckeler , P. E. L. Rakow , A. Schäfer , W. Söldner , T. Wettig