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Related papers: An exact algorithm for three-flavor QCD with $O(a)…

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The WHOT-QCD Collaboration is pushing forward a series of lattice studies of QCD at finite temperatures and densities using improved Wilson quarks. Because Wilson-type quarks require more computational resources than the more widely adopted…

High Energy Physics - Lattice · Physics 2012-05-25 Shinji Ejiri , Kazuyuki Kanaya , Takashi Umeda for WHOT-QCD Collaboration

We describe an algebraic algorithm which allows to express every one-loop lattice integral with gluon or Wilson-fermion propagators in terms of a small number of basic constants which can be computed with arbitrary high precision. Although…

High Energy Physics - Lattice · Physics 2009-10-28 Giuseppe Burgio , Sergio Caracciolo , Andrea Pelissetto

I describe a recent calculation (by me, Hoffmann, Liu, and Schaefer) of the chiral condensate in one-flavor QCD using numerical simulations with overlap fermions. The condensate is extracted by fitting the distribution of low lying…

High Energy Physics - Lattice · Physics 2008-11-26 Thomas DeGrand

Lattice QCD simulations at small lattice spacings and quark masses close to their physical values are technically challenging. In particular, the simulations can get trapped in the topological charge sectors of field space or may run into…

High Energy Physics - Lattice · Physics 2015-06-05 Martin Lüscher , Stefan Schaefer

QCD lattice simulations with 2+1 flavours typically start at rather large up-down and strange quark masses and extrapolate first the strange quark mass to its physical value and then the up-down quark mass. An alternative method of tuning…

We construct new Ginsparg-Wilson fermions for QCD by inserting an approximately chiral Dirac operator - which involves ingredients of a perfect action - into the overlap formula. This accelerates the convergence of the overlap Dirac…

High Energy Physics - Lattice · Physics 2010-04-05 W. Bietenholz

We publish BQCD as free software under the GNU General Public License. BQCD is a Hybrid Monte-Carlo program that simulates lattice QCD with dynamical Wilson fermions. It is one of the main production programs of the QCDSF collaboration. The…

High Energy Physics - Lattice · Physics 2011-03-31 Yoshifumi Nakamura , Hinnerk Stüben

We describe an explicit construction of approximate Ginsparg-Wilson fermions for QCD. We use ingredients of perfect action origin, and further elements. The spectrum of the lattice Dirac operator reveals the quality of the approximation. We…

High Energy Physics - Lattice · Physics 2009-10-31 W. Bietenholz , N. Eicker , I. Hip , K. Schilling

As a computationally less costly test case for full QCD, we investigate an SU(3) Yang-Mills theory coupled to a bosonic spinor field. This theory corresponds to QCD with minus two quark flavors and is known as the bermion model. Our central…

High Energy Physics - Lattice · Physics 2007-05-23 Bernd Gehrmann

We present results from the first large-scale study of two flavor QCD using domain wall fermions (DWF), a chirally symmetric fermion formulation which has proven to be very effective in the quenched approximation. We work on lattices of…

High Energy Physics - Lattice · Physics 2009-11-13 Y. Aoki , T. Blum , N. Christ , C. Dawson , K. Hashimoto , T. Izubuchi , J. W. Laiho , L. Levkova , M. Lin , R. Mawhinney , J. Noaki , S. Ohta , K. Orginos , A. Soni

In the presence of a non-vanishing chemical potential the eigenvalues of the Dirac operator become complex. We calculate spectral correlation functions of complex eigenvalues using a random matrix model approach. Our results apply to…

High Energy Physics - Theory · Physics 2009-11-07 G. Akemann

We present results of an ongoing study of two flavour QCD with Wilson fermions at finite temperature. We have used tree level Symanzik improvement in both the gauge and fermion part of the action. The phase diagram was previously determined…

High Energy Physics - Lattice · Physics 2009-10-31 F. Karsch , E. Laermann , M. Oevers , P. Schmidt

We present a study of the deconfinement phase transition of one-flavour QCD, using the multiboson algorithm. The mass of the Wilson fermions relevant for this study is moderately large and the non-hermitian multiboson method is a superior…

We study the deconfinement transition of $N_f=1$ QCD by the hybrid Monte Carlo algorithm with Wilson fermions. We calculate the Polyakov loop, its susceptibility and Binder cumulant and use the $\chi^2$ method to locate the phase transition…

High Energy Physics - Lattice · Physics 2009-11-10 Fumiyoshi Shoji , Tetsuya Takaishi

We study thermodynamic properties of 2+1 flavor QCD applying the Small Flow-time eXpansion (SFtX) method based on the gradient flow. The method provides us with a general way to compute correctly renormalized observables irrespective of…

High Energy Physics - Lattice · Physics 2019-10-30 Kazuyuki Kanaya , Atsushi Baba , Asobu Suzuki , Shinji Ejiri , Masakiyo Kitazawa , Hiroshi Suzuki , Yusuke Taniguchi , Takashi Umeda

We determine non-perturbatively the normalisation constant Z_m*Z_P/Z_A as well as the Symanzik coefficients b_m and b_A-b_P, required in O(a) improved quark mass renormalisation with Wilson fermions. The strategy underlying their…

An algorithm for separating the high- and low-frequency molecular dynamics modes in Hybrid Monte Carlo simulations of gauge theories with dynamical fermions is presented. The separation is based on splitting the pseudo-fermion action into…

High Energy Physics - Lattice · Physics 2008-11-26 A. Ali Khan , T. Bakeyev , M. Göckeler , R. Horsley , D. Pleiter , P. Rakow , A. Schäfer , G. Schierholz , H. Stüben

We present a general strategy aimed at generating $N_f=2+1+1$ configurations with quarks at their physical mass using maximally twisted mass fermions to ensure automatic $O(a)$ improvement, in the presence of a clover term tuned to reduce…

The increase with time of computer resources devoted to simulations of full QCD is spectacular. Yet the reduction of systematic errors is comparatively slow. This is due to the algorithmic complexity of the problem. I review, in elementary…

High Energy Physics - Lattice · Physics 2007-05-23 Philippe de Forcrand

We report on the status of the dynamical overlap QCD simulation project by the JLQCD collaboration. After completing two-flavor QCD simulation on a 16^3x32 lattice at lattice spacing a 0.12 fm, we started a series of runs with 2+1 flavors.…

High Energy Physics - Lattice · Physics 2008-11-26 JLQCD collaboration , S. Hashimoto , S. Aoki , H. Fukaya , T. Kaneko , H. Matsufuru , J. Noaki , T. Onogi , N. Yamada