English
Related papers

Related papers: Comparing matrix models and QCD lattice data with …

200 papers

We study the spectral gap of the Wilson--Dirac operator in two-flavour lattice QCD as a function of the lattice spacing $a$, the space-time volume $V$ and the current-quark mass $m$. It turns out that the median of the probability…

High Energy Physics - Lattice · Physics 2009-11-11 L. Del Debbio , L. Giusti , M. Lüscher , R. Petronzio , N. Tantalo

We discuss a new Random Matrix Model for QCD with a chemical potential that is based on the symmetries of the Dirac operator and can be solved exactly for all eigenvalue correlations for any number of flavors. In the microscopic limit of…

High Energy Physics - Lattice · Physics 2009-11-10 James C. Osborn

We confront the finite volume and small quark mass behaviour of the scalar condensate, determined numerically in quenched lattice QCD using Neuberger fermions, with predictions of quenched chiral perturbation theory. We find that quenched…

High Energy Physics - Lattice · Physics 2009-10-31 P. Hernandez , K. Jansen , L. Lellouch

In this lecture we review recent lattice QCD studies of the statistical properties of the eigenvalues of the QCD Dirac operator. We find that the fluctuations of the smallest Dirac eigenvalues are described by chiral Random Matrix Theories…

High Energy Physics - Lattice · Physics 2009-10-31 J. J. M. Verbaarschot

We present numerical simulation of QCD with two dynamical quark flavors described by the overlap fermion action on a $16^3\times 32\times (0.12 {\rm fm})^4$ lattice. We calculate pseudo-scalar masses and decay constants and investigate…

High Energy Physics - Lattice · Physics 2009-04-14 J. Noaki , S. Aoki , H. Fukaya , S. Hashimoto , T. Kaneko , H. Matsufuru , T. Onogi , E. Shintani , N. Yamada

Recent results from the UKQCD Collaboration's dynamical simulations are presented. The main feature of these ensembles is that they have a fixed lattice spacing and volume, but varying sea quark mass from infinite (corresponding to the…

High Energy Physics - Lattice · Physics 2009-11-07 Chris Allton

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

A simulation of quenched QCD with the overlap Dirac operator has been completed using 100 Wilson gauge configurations at beta = 6 on an 18^3 x 64 lattice and at beta = 5.85 on a 14^3 x 48 lattice, both in Landau gauge. We present results…

We study the singular values of the Dirac operator in dense QCD-like theories at zero temperature. The Dirac singular values are real and nonnegative at any nonzero quark density. The scale of their spectrum is set by the diquark…

High Energy Physics - Phenomenology · Physics 2011-12-15 Takuya Kanazawa , Tilo Wettig , Naoki Yamamoto

Using an integration formula recently derived by Conrey, Farmer and Zirnbauer, we calculate the expectation value of the phase factor of the fermion determinant for the staggered lattice QCD action in one dimension. We show that the…

High Energy Physics - Theory · Physics 2008-11-26 L. Ravagli , J. J. M. 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 perform numerical simulations of lattice QCD with two flavors of dynamical overlap quarks, which have exact chiral symmetry on the lattice. While this fermion discretization is computationally demanding, we demonstrate the feasibility to…

The microscopic spectral density of the Hermitian Wilson-Dirac operator is computed numerically in quenched lattice QCD. We demonstrate that the results given for fixed index of the Wilson-Dirac operator can be matched by the predictions…

High Energy Physics - Lattice · Physics 2013-05-30 P. H. Damgaard , U. M. Heller , K. Splittorff

We summarize the analytical solution of the Chiral Perturbation Theory for the Hermitian Wilson Dirac operator of $N_c=2$ QCD with quarks in the fundamental representation. Results have been obtained for the quenched microscopic spectral…

High Energy Physics - Lattice · Physics 2015-05-20 Mario Kieburg , Jacobus Verbaarschot , Savvas Zafeiropoulos

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 present details of simulations for the light hadron spectrum in quenched QCD carried out on the CP-PACS parallel computer. Simulations are made with the Wilson quark action and the plaquette gauge action on 32^3x56 - 64^3x112 lattices at…

Simulations of quenched $QCD$ at relatively small but {\it nonzero} chemical potential $\mu$ on $32 \times 16^3$ lattices indicate that the nucleon screening mass decreases linearly as $\mu$ increases predicting a critical chemical…

High Energy Physics - Lattice · Physics 2009-10-22 J. B. Kogut , M-P Lombardo , D. K. Sinclair

For QCD at non-zero chemical potential $\mu$, the Dirac eigenvalues are scattered in the complex plane. We define a notion of ordering for individual eigenvalues in this case and derive the distributions of individual eigenvalues from…

High Energy Physics - Lattice · Physics 2009-01-14 Gernot Akemann , Jacques Bloch , Leonid Shifrin , Tilo Wettig

In this lecture we discuss various aspects of QCD at nonzero chemical potential, including its phase diagram and the Dirac spectrum, and summarize what chiral random matrix theory has contributed to this subject. To illustrate the…

High Energy Physics - Phenomenology · Physics 2017-08-23 K. Splittorff , J. J. M. Verbaarschot

We present a method of simulating lattice QCD at nonzero chemical potential in the chiral limit. By adding a weak four-fermi interaction to the standard staggered fermion SU(3) QCD action, we produce an algorithm in which the limit of…

High Energy Physics - Lattice · Physics 2009-10-28 I. M. Barbour , S. E. Morrison , John B. Kogut